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Sodium regulation of GAF domain function

Cann, M.J.



Cyclic nucleotide PDEs (phosphodiesterases) regulate cellular levels of cAMP and cGMP by controlling the rate of degradation. Several mammalian PDE isoforms possess N-terminal GAF (found in cGMP PDEs, Anabaena adenylate cyclases and Escherichia coli FhlA; where FhlA is formate hydrogen lyase transcriptional activator) domains that bind cyclic nucleotides. Similarly, the CyaB1 and CyaB2 ACs (adenylate cyclases) of the cyanobacterium Anabaena PCC 7120 bind cAMP through one (CyaB1) or two (CyaB2) N-terminal GAF domains and mediate autoregulation of the AC domain. Sodium inhibits the activity of CyaB1, CyaB2 and mammalian PDE2A in vitro through modulation of GAF domain function. Furthermore, genetic ablation of cyaB1 and cyaB2 gives rise to Anabaena strains defective in homoeostasis at limiting sodium. Sodium regulation of GAF domain function has therefore been conserved since the eukaryotic/prokaryotic divergence. The GAF domain is the first identified protein domain to directly sense and signal changes in environmental sodium.


Cann, M. (2007). Sodium regulation of GAF domain function. Biochemical Society Transactions, 35(5), 1032-1034.

Journal Article Type Article
Publication Date 2007-11
Journal Biochemical Society Transactions
Print ISSN 0300-5127
Electronic ISSN 1470-8752
Publisher Portland Press
Peer Reviewed Peer Reviewed
Volume 35
Issue 5
Pages 1032-1034
Keywords Adenylate cyclase, Cyanobacterium, Cyclic nuclectide, GAF domain, Phosphodiesterase (PDF), Sodium.