Generic temperature compensation of biological clocks by autonomous regulation of catalyst concentration.

PubMed

Hatakeyama, Tetsuhiro S; Kaneko, Kunihiko

2012-05-22

Circadian clocks--ubiquitous in life forms ranging from bacteria to multicellular organisms--often exhibit intrinsic temperature compensation; the period of circadian oscillators is maintained constant over a range of physiological temperatures, despite the expected Arrhenius form for the reaction coefficient. Observations have shown that the amplitude of the oscillation depends on the temperature but the period does not; this suggests that although not every reaction step is temperature independent, the total system comprising several reactions still exhibits compensation. Here we present a general mechanism for such temperature compensation. Consider a system with multiple activation energy barriers for reactions, with a common enzyme shared across several reaction steps. The steps with the highest activation energy rate-limit the cycle when the temperature is not high. If the total abundance of the enzyme is limited, the amount of free enzyme available to catalyze a specific reaction decreases as more substrates bind to the common enzyme. We show that this change in free enzyme abundance compensates for the Arrhenius-type temperature dependence of the reaction coefficient. Taking the example of circadian clocks with cyanobacterial proteins KaiABC, consisting of several phosphorylation sites, we show that this temperature compensation mechanism is indeed valid. Specifically, if the activation energy for phosphorylation is larger than that for dephosphorylation, competition for KaiA shared among the phosphorylation reactions leads to temperature compensation. Moreover, taking a simpler model, we demonstrate the generality of the proposed compensation mechanism, suggesting relevance not only to circadian clocks but to other (bio)chemical oscillators as well.

A Plan to Develop a Red Tide Warning System for Seawater Desalination Process Management

NASA Astrophysics Data System (ADS)

Kim, Tae Woo; Yun, Hong Sik

2017-04-01

The holt of the seawater desalination process for fifty five days due to the eight-month long red tide in 2008 in the Persian Gulf, the Middle East, had lost about 10 billion KRW. The POSCO Seawater Desalination facility, located in Gwangyang Bay Area in the Southern Sea, has produced 30,000 tons of fresh water per day since 2014. Since there has been an incident of red time in the area for three months in August, 2012, it is necessary to establish a warning system for red tide that threatens the stable operation of the seawater desalination facility. A red tide warning system can offer the seawater desalination facility manager customized services on red tide information and potential red tide inflow to the water intake. This study aimed to develop a red tide warning system in Gwangyang Bay Area by combining RS, modeling and monitoring technologies, which provides red tide forecasting information with which to effectively control the seawater desalination process. Using the proposed system, the seawater desalination facility manager can take phased measures to cope with the inflow of red tide. ACKNOWLEDGMENTS This research was supported by a grant(16IFIP-C088924-03) from Industrial Facilities & Infrastructure Research Program funded by Ministry of Land, Infrastructure and Transport(MOLIT) of the Korea government and the Korea Agency for Infrastructure Technology Advancement (KAIA). This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2014R1A1A2054975).

War-related extremity injuries in children: 89 cases managed in a combat support hospital in Afghanistan.

PubMed

Bertani, A; Mathieu, L; Dahan, J-L; Launay, F; Rongiéras, F; Rigal, S

2015-05-01

Meeting paediatric needs is among the priorities of western healthcare providers working in Afghanistan. Insufficient information is available on paediatric wartime injuries to the extremities. Our objective here was to describe these injuries and their management on the field. We retrospectively reviewed consecutive cases of injuries to the extremities in children (< 16 years of age) due to weapons and managed at the Kabul International Airport (KaIA) Combat Support Hospital between June 2009 and April 2013. We identified 89 patients with a mean age of 10.2 ± 3.5 years and a total of 137 elemental lesions. Explosive devices accounted for most injuries (78.6%) and carried a significantly higher risk of multiple lesions. There were 54 bone lesions (traumatic amputations and fractures) and 83 soft-tissue lesions. The amputation rate was 18%. Presence of bone lesions was associated with a higher risk of injury to blood vessels and nerves. Of the 89 patients, four (4.5%) died and eight (9%) were transferred elsewhere. Of the 77 remaining patients, at last follow-up (median, one month; range, 0.1-16 months), 73 (95%) had achieved a full recovery (healed wound and/or fracture) or were recovering with no expectation that further surgery would be needed. Despite the absence of paediatric surgeons, the combat support hospital provided appropriate care at the limb salvage and reconstruction phases. The highly specialised treatments needed to manage sequelae were very rarely provided. These treatments probably deserve to be developed in combat support hospitals. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Human retroviruses and AIDS 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korber, B.; Foley, B.; Leitner, T.

1997-12-01

This compendium is the result of an effort to compile, organize, and rapidly publish as much relevant molecular data concerning the human immunodeficiency viruses (HIV) and related retroviruses as possible. The scope of the compendium and database is best summarized by the four parts that it comprises: (1) Nucleic Acid Alignments, (2) Amino Acid Alignments, (3) Reviews and Analyses, and (4) Related Sequences. Information within all the parts is updated throughout the year on the Web site, http://hiv-web.lanl.gov. This year we are not including floppy diskettes as the entire compendium is available both at our Web site and at ourmore » ftp site. If you need floppy diskettes please contact either Bette Korber (btk@t10.lanl.gov) or Kersti Rock (karm@t10.lanl.gov) by email or fax ((505) 665-4453). While this publication could take the form of a review or sequence monograph, it is not so conceived. Instead, the literature from which the database is derived has simply been summarized and some elementary computational analyses have been performed upon the data. Interpretation and commentary have been avoided insofar as possible so that the reader can form his or her own judgments concerning the complex information. The exception to this are reviews submitted by experts in areas deemed of particular and basic importance to research involving AIDS viral sequence information. These are included in Part III, and are contributed by scientists with particular expertise in the area of interest. In addition to the general descriptions below of the parts of the compendium, the user should read the individual introductions for each part.« less

Cephalic region war injuries in children: Experience in French NATO hospital in Kabul Afghanistan.

PubMed

Chehab, Hussam El; Agard, Emilie; Dot, Corinne

2018-06-09

The NATO KAIA Hospital (Kabul International Airport), under French command, provided medical support for NATO forces in the Kabul region from 2009 to 2014. Medical assistance to civilians was an additional mission which included support for children who were war injured. The objective of this study was to analyze characteristics of cephalic injuries in children victims of war trauma. A retrospective study was conducted and commenced with the hospital opening (July 2009) to March 2012 on all children (<15years) with war trauma. We distinguished cephalic lesions in cranial (neuro-surgical), ophthalmological and neck regions. We analyzed mechanism, region, severity score, surgeries and resuscitation efforts. 217 children were operated on with 81 war traumas (mean age 10.2years). 36 children (44.4%) had a cephalic injury. 52.9% of the injured had an ophthalmological injury, 38.2% a cranial region injury and 29.4% a neck lesion. Mortality rate was 5.6% (1 hemorrhagic shock and 1 cerebral wound) in this cephalic lesion group. Ophthalmic injuries were the most common of cephalic injuries; 19 children of which 7 had a bilateral injury (26 eyes). In this group, fragmentary injuries were the most frequent (64% of eyes). In cerebral lesion group, the lesions were linked to a bullet or a shrapnel in 9 of 13 children. This mechanism systematically caused a crania-cerebral wound. Explosion (fragmentary and shrapnel) was the most important in the neck lesions (7 children of 10). The cephalic lesions were the second most common region in children during our experience in Afghanistan. Lack of protection (helmet) in children may explain the frequency of cephalic wounds. Copyright © 2018 Elsevier Ltd. All rights reserved.

Radon as a tracer to characterize the interactions between groundwater and surface water around the ground source heat pump system in riverside area

NASA Astrophysics Data System (ADS)

Kim, Jaeyeon; Lee, Seong-Sun; Lee, Kang-Kun

2016-04-01

The interaction characteristics between groundwater and surface water was examined by using Radon-222 at Han River Environmental Research Center (HRERC) in Korea where a geothermal resource using indirect open loop ground source heat pump (GSHP) has been developed. For designing a high efficiency performance of the open loop system in shallow aquifer, the riverside area was selected for great advantage of full capacity of well. From this reason groundwater properties of the study site can be easily influenced by influx of surrounding Han River. Therefore, 12 groundwater wells were used for monitoring radon concentration and groundwater level with fluctuation of river stage from May, 2014 to Apr., 2015. The short term monitoring data showed that the radon concentration was changed in accordance with flow meter data which was reflected well by the river stage fluctuation. The spatial distribution of radon concentration from long term monitoring data was also found to be affected by water level fluctuation by nearby dam activity and seasonal effect such as heavy rainfall and groundwater pumping. The estimated residence time indicates that river flows to the study site change its direction according to the combined effect of river stage and groundwater hydrology. In the linear regression of the values, flow velocities were yielded around 0.04 to 0.25 m/day which were similar to flow meter data. These results reveal that Radon-222 can be used as an appropriate environmental tracer in examining the characteristics of interaction in consideration of fluctuating river flow on operation of GSHP in the riverside area. ACKNOWLEDGEMENT This work was supported by the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+) in "Water Resources Management Program (code 11 Technology Innovation C05)" of the MOLIT and the KAIA in Korea.

CryoEM and Molecular Dynamics of the Circadian KaiB-KaiC Complex Indicates That KaiB Monomers Interact with KaiC and Block ATP Binding Clefts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villarreal, Seth A.; Pattanayek, Rekha; Williams, Dewight R.

The circadian control of cellular processes in cyanobacteria is regulated by a posttranslational oscillator formed by three Kai proteins. During the oscillator cycle, KaiA serves to promote autophosphorylation of KaiC while KaiB counteracts this effect. Here, we present a crystallographic structure of the wild-type Synechococcus elongatus KaiB and a cryo-electron microscopy (cryoEM) structure of a KaiBC complex. The crystal structure shows the expected dimer core structure and significant conformational variations of the KaiB C-terminal region, which is functionally important in maintaining rhythmicity. The KaiBC sample was formed with a C-terminally truncated form of KaiC, KaiC-Δ489, which is persistently phosphorylated. Themore » KaiB–KaiC-Δ489 structure reveals that the KaiC hexamer can bind six monomers of KaiB, which form a continuous ring of density in the KaiBC complex. We performed cryoEM-guided molecular dynamics flexible fitting simulations with crystal structures of KaiB and KaiC to probe the KaiBC protein–protein interface. This analysis indicated a favorable binding mode for the KaiB monomer on the CII end of KaiC, involving two adjacent KaiC subunits and spanning an ATP binding cleft. A KaiC mutation, R468C, which has been shown to affect the affinity of KaiB for KaiC and lengthen the period in a bioluminescence rhythm assay, is found within the middle of the predicted KaiBC interface. The proposed KaiB binding mode blocks access to the ATP binding cleft in the CII ring of KaiC, which provides insight into how KaiB might influence the phosphorylation status of KaiC.« less

Active output state of the Synechococcus Kai circadian oscillator

PubMed Central

Paddock, Mark L.; Boyd, Joseph S.; Adin, Dawn M.; Golden, Susan S.

2013-01-01

The mechanisms by which cellular oscillators keep time and transmit temporal information are poorly understood. In cyanobacteria, the timekeeping aspect of the circadian oscillator, composed of the KaiA, KaiB, and KaiC proteins, involves a cyclic progression of phosphorylation states at Ser431 and Thr432 of KaiC. Elucidating the mechanism that uses this temporal information to modulate gene expression is complicated by unknowns regarding the number, structure, and regulatory effects of output components. To identify oscillator signaling states without a complete description of the output machinery, we defined a simple metric, Kai-complex output activity (KOA), that represents the difference in expression of reporter genes between strains that carry specific variants of KaiC and baseline strains that lack KaiC. In the absence of the oscillator, expression of the class 1 paradigm promoter PkaiBC was locked at its usual peak level; conversely, that of the class 2 paradigm promoter PpurF was locked at its trough level. However, for both classes of promoters, peak KOA in wild-type strains coincided late in the circadian cycle near subjective dawn, when KaiC-pST becomes most prevalent (Ser431 is phosphorylated and Thr432 is not). Analogously, peak KOA was detected specifically for the phosphomimetic of KaiC-pST (KaiC-ET). Notably, peak KOA required KaiB, indicating that a KaiBC complex is involved in the output activity. We also found evidence that phosphorylated RpaA (regulator of phycobilisome associated) represses an RpaA-independent output of KOA. A simple mathematical expression successfully simulated two key features of the oscillator—the time of peak KOA and the peak-to-trough amplitude changes. PMID:24043774

Active output state of the Synechococcus Kai circadian oscillator.

PubMed

Paddock, Mark L; Boyd, Joseph S; Adin, Dawn M; Golden, Susan S

2013-10-01

The mechanisms by which cellular oscillators keep time and transmit temporal information are poorly understood. In cyanobacteria, the timekeeping aspect of the circadian oscillator, composed of the KaiA, KaiB, and KaiC proteins, involves a cyclic progression of phosphorylation states at Ser431 and Thr432 of KaiC. Elucidating the mechanism that uses this temporal information to modulate gene expression is complicated by unknowns regarding the number, structure, and regulatory effects of output components. To identify oscillator signaling states without a complete description of the output machinery, we defined a simple metric, Kai-complex output activity (KOA), that represents the difference in expression of reporter genes between strains that carry specific variants of KaiC and baseline strains that lack KaiC. In the absence of the oscillator, expression of the class 1 paradigm promoter P(kaiBC) was locked at its usual peak level; conversely, that of the class 2 paradigm promoter P(purF) was locked at its trough level. However, for both classes of promoters, peak KOA in wild-type strains coincided late in the circadian cycle near subjective dawn, when KaiC-pST becomes most prevalent (Ser431 is phosphorylated and Thr432 is not). Analogously, peak KOA was detected specifically for the phosphomimetic of KaiC-pST (KaiC-ET). Notably, peak KOA required KaiB, indicating that a KaiBC complex is involved in the output activity. We also found evidence that phosphorylated RpaA (regulator of phycobilisome associated) represses an RpaA-independent output of KOA. A simple mathematical expression successfully simulated two key features of the oscillator-the time of peak KOA and the peak-to-trough amplitude changes.

Development of Radar-Satellite Blended QPF (Quantitative Precipitation Forecast) Technique for heavy rainfall

NASA Astrophysics Data System (ADS)

Jang, Sangmin; Yoon, Sunkwon; Rhee, Jinyoung; Park, Kyungwon

2016-04-01

Ministry of Land, Infrastructure and Transport (MOLIT) of Korea government and Korea Agency for Infrastructure Technology Advancement (KAIA).

Stability and Noise in the Cyanobacterial Circadian Clock

NASA Astrophysics Data System (ADS)

Mihalcescu, Irina

2008-03-01

Accuracy in cellular function has to be achieved despite random fluctuations (noise) in the concentrations of different molecular constituents inside and outside the cell. Single cell in vivo monitoring reveals that individual cells generate autonomous circadian rhythms in protein abundance. In multi-cellular organisms, the individual cell rhythms appear to be noisy with drifting phases and frequencies. However, the whole organism is significantly more accurate, the temporal precision being achieved most probably via intercellular coupling of the individual noisy oscillators. In cyanobacteria, we have shown that single cell oscillators are impressively stable and a first estimation rules out strong intercellular coupling. Interestingly, these prokaryotes also have the simplest molecular mechanism at the heart of their circadian clock. In the absence of transcriptional activity in vivo, as well alone in vitro, the three clock proteins KaiA, KaiB and KaiC generate a self-sustained circadian oscillation of autophosphorylation and dephosphorylation. Recent chemical kinetics models provide a possible understanding of the three-protein oscillator, but the measured in vivo stability remains yet unexplained. Is the clock stability a built-in property for each bacterium or does a weak intercellular coupling, make them appear like that? To address this question we first theoretically designed our experiment to be able to distinguish coupling, even weak, from phase diffusion. As the precision of our evaluation increases with the length of the experiments, we continuously monitor, for a couple of weeks, mixtures of cell populations with different initial phases. The inherent experimental noise contribution, initially dominant, is reduced by enhanced statistics. In addition, in situ entrainment experiments confirm our ability to detect a coupling of the circadian oscillator to an external force and to describe explicitly the dynamic change of the mean phase. We report a value

Application of δ18O, δD, 3H-3He and CFCs to characterize the nitrate contamination of groundwater in Eumsung, Korea

NASA Astrophysics Data System (ADS)

Ju, Y. J.; Kaown, D.; Hahm, D.; Kim, I.; Lee, S. S.; Koh, E. H.; Kim, M.; Yoon, Y. Y.; Lee, K. K.

2015-12-01

We measured the major ions, stable oxygen and hydrogen isotopes, 3H-3He and CFCs concentration in groundwater to identify the characteristics of nitrate contamination and to understand the groundwater recharge patterns. In this study, 17 groundwater samples were collected for 5days (from March 3rd to 7th, 2015) in Eumseong, Korea. In the study area, NO3- concentrations in some groundwater samples (16 of 17) ranged from 5.7 to 103.7 mg/L (avg. 43.3 mg/L), which were substantially higher than the drinking water quality standard (10 mg/L). These excess NO3- inputs in groundwater seem to be originated from the agricultural use of chemical fertilizers because major ions associated with fertilizers were significantly correlated with NO3-. It seems that major groundwater recharge event during monsoon season is highly probable from the analysis of δ18O and δD. The apparent groundwater age using 3H-3He and CFCs varies from 5 to 40 yrs although the study area is small (1 km2). For the samples showed large deficiency of 3He, the sensitivity analysis was performed using NOBLE 90 in an effort to quantify the degassed amount. Since nitrate sources are quite evenly distributed through the field site, groundwater ages from shallow aquifer is inversely correlated with the nitrate concentrations. Our result implies that the 3H-3He ratio can be a useful indicator of tracing the recharge pattern of groundwater but also the nitrate loading characteristic in a small scale agricultural area. Acknowlegments: Financial support was provided by the "R&D Project on Environmental Management of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003) and the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+)" in "Water Resources Management Program (code 11 Technology Innovation C05)" of the MOLIT and the KAIA in Korea.

An Integrated Approach on Groundwater Flow and Heat/Solute Transport for Sustainable Groundwater Source Heat Pump (GWHP) System Operation

NASA Astrophysics Data System (ADS)

Park, D. K.; Bae, G. O.; Joun, W.; Park, B. H.; Park, J.; Park, I.; Lee, K. K.

2015-12-01

for the sustainable GWHP system operation. Acknowledgment: This work was supported by the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+)" in "Water Resources Management Program (code 11 Technology Innovation C05)" of the MOLIT and the KAIA in Korea.

Architecture and mechanism of the central gear in an ancient molecular timer.

PubMed

Egli, Martin

2017-03-01

Molecular clocks are the product of natural selection in organisms from bacteria to human and their appearance early in evolution such as in the prokaryotic cyanobacterium Synechococcus elongatus suggests that these timers served a crucial role in genetic fitness. Thus, a clock allows cyanobacteria relying on photosynthesis and nitrogen fixation to temporally space the two processes and avoid exposure of nitrogenase carrying out fixation to high levels of oxygen produced during photosynthesis. Fascinating properties of molecular clocks are the long time constant, their precision and temperature compensation. Although these are hallmarks of all circadian oscillators, the actual cogs and gears that control clocks vary widely between organisms, indicating that circadian timers evolved convergently multiple times, owing to the selective pressure of an environment with a daily light/dark cycle. In S. elongatus , the three proteins KaiA, KaiB and KaiC in the presence of ATP constitute a so-called post-translational oscillator (PTO). The KaiABC PTO can be reconstituted in an Eppendorf tube and keeps time in a temperature-compensated manner. The ease by which the KaiABC clock can be studied in vitro has made it the best-investigated molecular clock system. Over the last decade, structures of all three Kai proteins and some of their complexes have emerged and mechanistic aspects have been analysed in considerable detail. This review focuses on the central gear of the S. elongatus clock and only enzyme among the three proteins: KaiC. Our determination of the three-dimensional structure of KaiC early in the quest for a better understanding of the inner workings of the cyanobacterial timer revealed its unusual architecture and conformational differences and unique features of the two RecA-like domains constituting KaiC. The structure also pinpointed phosphorylation sites and differential interactions with ATP molecules at subunit interfaces, and helped guide experiments to

Operational Characteristics Identification and Simulation Model Verification for Incheon International Airport

NASA Technical Reports Server (NTRS)

Eun, Yeonju; Jeon, Daekeun; Lee, Hanbong; Zhu, Zhifan; Jung, Yoon C.; Jeong, Myeongsook; Kim, Hyounkyong; Oh, Eunmi; Hong, Sungkwon; Lee, Junwon

2016-01-01

NASA's Airspace Technology Demonstration - 2 (ATD-2) project for technology demonstration of Integrated Arrival/Departure/Surface (ADS) operations at CLT. This study is a part of the international research collaboration between KAIA (Korea Agency for Infrastructure Technology Advancement)/KARI (Korea Aerospace Research Institute) and NASA, which is being conducted to validate the effectiveness of SARDA concept as a controller decision support tool for departure and surface management of ICN. This paper presents the preliminary results of the collaboration effort. It includes investigation of the operational environment of ICN, data analysis for identification of the operational characteristics of the airport, construction and verification of airport simulation model using Surface Operations Simulator and Scheduler (SOSS), NASA's fast-time simulation tool.

Operational Characteristics Identification and Simulation Model Verification for Incheon International Airport

NASA Technical Reports Server (NTRS)

Eun, Yeonju; Jeon, Daekeun; Lee, Hanbong; Zhu, Zhifan; Jung, Yoon C.; Jeong, Myeongsook; Kim, Hyounkyong; Oh, Eunmi; Hong, Sungkwon; Lee, Junwon

2016-01-01

integrated into NASA's Airspace Technology Demonstration-2 (ATD-2) project for technology demonstration of Integrated Arrival-Departure-Surface (IADS) operations at CLT. This study is a part of the international research collaboration between KAIA (Korea Agency for Infrastructure Technology Advancement), KARI (Korea Aerospace Research Institute) and NASA, which is being conducted to validate the effectiveness of SARDA concept as a controller decision support tool for departure and surface management of ICN. This paper presents the preliminary results of the collaboration effort. It includes investigation of the operational environment of ICN, data analysis for identification of the operational characteristics of the airport, construction and verification of airport simulation model using Surface Operations Simulator and Scheduler (SOSS), NASA's fast-time simulation tool.

Dephosphorylation of the Core Clock Protein KaiC in the Cyanobacterial KaiABC Circadian Oscillator Proceeds via an ATP Synthase Mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Egli, Martin; Mori, Tetsuya; Pattanayek, Rekha

The circadian clock of the cyanobacterium Synechococcus elongatus can be reconstituted in vitro from three proteins, KaiA, KaiB, and KaiC in the presence of ATP, to tick in a temperature-compensated manner. KaiC, the central cog of this oscillator, forms a homohexamer with 12 ATP molecules bound between its N- and C-terminal domains and exhibits unusual properties. Both the N-terminal (CI) and C-terminal (CII) domains harbor ATPase activity, and the subunit interfaces between CII domains are the sites of autokinase and autophosphatase activities. Hydrolysis of ATP correlates with phosphorylation at threonine and serine sites across subunits in an orchestrated manner, suchmore » that first T432 and then S431 are phosphorylated, followed by dephosphorylation of these residues in the same order. Although structural work has provided insight into the mechanisms of ATPase and kinase, the location and mechanism of the phosphatase have remained enigmatic. From the available experimental data based on a range of approaches, including KaiC crystal structures and small-angle X-ray scattering models, metal ion dependence, site-directed mutagenesis (i.e., E318, the general base), and measurements of the associated clock periods, phosphorylation patterns, and dephosphorylation courses as well as a lack of sequence motifs in KaiC that are typically associated with known phosphatases, we hypothesized that KaiCII makes use of the same active site for phosphorylation and dephosphorlyation. We observed that wild-type KaiC (wt-KaiC) exhibits an ATP synthase activity that is significantly reduced in the T432A/S431A mutant. We interpret the first observation as evidence that KaiCII is a phosphotransferase instead of a phosphatase and the second that the enzyme is capable of generating ATP, both from ADP and P{sub i} (in a reversal of the ATPase reaction) and from ADP and P-T432/P-S431 (dephosphorylation). This new concept regarding the mechanism of dephosphorylation is also supported