PMID- 26797504
OWN - NLM
STAT- MEDLINE
DCOM- 20161017
LR  - 20181113
IS  - 1875-8355 (Electronic)
IS  - 1572-3887 (Linking)
VI  - 35
IP  - 1
DP  - 2016 Feb
TI  - Post-translational Regulation of Hexokinase Function and Protein Stability in the 
      Aestivating Frog Xenopus laevis.
PG  - 61-71
LID - 10.1007/s10930-016-9647-0 [doi]
AB  - Xenopus laevis endure substantial dehydration which can impose hypoxic stress due 
      to impaired blood flow. Tissues may increase reliance on anaerobic glycolysis for 
      energy production making the regulation of hexokinase (HK) important. We 
      investigated the enzymatic properties and phosphorylation state of purified HK 
      from the muscle of control and dehydrated (30% total body water lost) frogs. 
      Bioinformatic tools were also applied to analyze the structural implication of HK 
      phosphorylation in silico. HK from the muscle of dehydrated frogs showed a 
      significantly higher Vmax (3.4-fold) and Km for glucose (2.4-fold) compared with 
      control HK but the Km for ATP was unaltered. HK from dehydrated frogs also showed 
      greater phosphoserine content (20% increase) and lower phosphothreonine (22% 
      decrease) content compared to control HK. Control HK had a higher melting 
      temperature (Tm = 61.9  degrees C) than from dehydrated (Tm = 54.2  degrees C) frogs when 
      thermostability was tested using differential scanning fluorimetry. In silico 
      phosphorylation of a Xenopus HK caused alterations in active site binding, 
      corroborating phosphorylation as the probable mechanism for kinetic regulation. 
      Physiological consequences of dehydration-induced HK phosphorylation appear to 
      facilitate glycolytic metabolism in hypoxic situations. Augmented HK function 
      increases the ability of Xenopus to overcome compromised oxidative 
      phosphorylation associated with ischemia during dehydration.
FAU - Childers, Christine L
AU  - Childers CL
AD  - Department of Biology, Institute of Biochemistry, Carleton University, Ottawa, 
      ON, Canada.
FAU - Storey, Kenneth B
AU  - Storey KB
AD  - Department of Biology, Institute of Biochemistry, Carleton University, Ottawa, 
      ON, Canada. kenneth_storey@carleton.ca.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Protein J
JT  - The protein journal
JID - 101212092
RN  - EC 2.7.1.1 (Hexokinase)
SB  - IM
MH  - Animals
MH  - Computer Simulation
MH  - Dehydration
MH  - Enzyme Stability
MH  - Hexokinase/*chemistry/*metabolism
MH  - Male
MH  - Phosphorylation
MH  - Protein Processing, Post-Translational
MH  - Temperature
MH  - Xenopus laevis/*metabolism/*physiology
OTO - NOTNLM
OT  - Dehydration
OT  - Hexokinase
OT  - Metabolism
OT  - Molecular operating environment
OT  - Phosphorylation
OT  - Xenopus laevis
EDAT- 2016/01/23 06:00
MHDA- 2016/10/19 06:00
CRDT- 2016/01/23 06:00
PHST- 2016/01/23 06:00 [entrez]
PHST- 2016/01/23 06:00 [pubmed]
PHST- 2016/10/19 06:00 [medline]
AID - 10.1007/s10930-016-9647-0 [pii]
AID - 10.1007/s10930-016-9647-0 [doi]
PST - ppublish
SO  - Protein J. 2016 Feb;35(1):61-71. doi: 10.1007/s10930-016-9647-0.