Identification of syntaxin-1A sites of phosphorylation by casein kinase I and casein kinase II.
Casein kinases I (CKI) are serine/threonine protein kinases widely expressed in a range of eukaryotes including yeast, mammals and plants. They have been shown to play a role in diverse physiological events including membrane trafficking. CKI alpha is associated with synaptic vesicles and phosphorylates some synaptic vesicle associated proteins including SV2. In this report, we show that syntaxin-1A is phosphorylated in vitro by CKI on Thr21. Casein kinase II (CKII) has been shown previously to phosphorylate syntaxin-1A in vitro and we have identified Ser14 as the CKII phosphorylation site, which is known to be phosphorylated in vivo. As syntaxin-1A plays a key role in the regulation of neurotransmitter release by forming part of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex, we propose that CKI may play a role in synaptic vesicle exocytosis.
Dubois
Thierry
T
The University of Edinburgh, Division of Biomedical and Clinical Laboratory Sciences, UK. thierry.dubois@curie.fr
Kerai
Preeti
P
Learmonth
Michele
M
Cronshaw
Andy
A
Aitken
Alastair
A
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism*; D047390:Casein Kinase II; D047388:Casein Kinases; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D050827:Syntaxin 1; D013912:Threonine / Q000378:metabolism
D000954:Antigens, Surface; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; C494213:Stx1a protein, rat; D050827:Syntaxin 1; D013912:Threonine; D012694:Serine; D011494:Protein Kinases; D047390:Casein Kinase II; D047388:Casein Kinases; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases