CVAK104 is a novel poly-L-lysine-stimulated kinase that targets the beta2-subunit of AP2.
Isolated clathrin adaptor protein (AP) preparations are known to co-fractionate with endogenous kinase activities, including poly-L-lysine-stimulated kinases that target various constituents of the clathrin coat. We have identified CVAK104 (a coated vesicle-associated kinase of 104 kDa) using a mass spectroscopic analysis of adaptor protein preparations. CVAK104 is a novel serine/threonine kinase that belongs to the SCY1-like family of protein kinases, previously thought to be catalytically inactive. We found that CVAK104 co-fractionates with adaptor protein preparations extracted from clathrin-coated vesicles and directly binds to both clathrin and the plasma membrane adaptor, AP2. CVAK104 binds ATP, and kinase assays indicate that it functions in vitro as a poly-L-lysine-stimulated kinase that is capable of autophosphorylation and phosphorylating the beta2-adaptin subunit of AP2.
Conner
Sean D
SD
Department of Genetics, Cell Biology, and Development, The University of Minnesota, Minneapolis, Minnesota 55455, USA. sdconner@umn.edu
Schmid
Sandra L
SL
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D002384:Catalysis; D002417:Cattle; D002966:Clathrin / Q000737:chemistry / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008239:Lysine / Q000737:chemistry*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010770:Phosphotransferases / Q000737:chemistry*; D010802:Phylogeny; D011107:Polylysine / Q000737:chemistry; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000502:physiology*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry; D040901:Proteomics / Q000379:methods; D013347:Subcellular Fractions; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000737:chemistry*
D002966:Clathrin; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D011506:Proteins; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D011107:Polylysine; D005982:Glutathione Transferase; D010770:Phosphotransferases; D017346:Protein Serine-Threonine Kinases; C501863:SCYL2 protein, human; D008239:Lysine