SIMILAR SUBSTRATE RECOGNITION MOTIFS FOR MAMMALIAN AMP-ACTIVATED PROTEIN-KINASE, HIGHER-PLANT HMG-COA REDUCTASE KINASE-A, YEAST SNF1, AND MAMMALIAN CALMODULIN-DEPENDENT PROTEIN-KINASE-I

We have analysed phosphorylation of the synthetic peptide AMARAASAAALA RRR, and 23 variants, by mammalian, higher plant and yeast members of the SNF1 protein kinase subfamily (AMP-activated protein kinase (AMPK) , HMG-CoA reductase kinase (HRK-A), and SNF1 itself), and by mammalian calnodulin-dependent protein kinase I (CaMKI). These four kinases rec ognize motifs which are very similar, although distinguishable, Our st udies define the following recognition motifs: AMPK: Phi(X,beta)XXS/TX XX Phi; HRK-A: Phi(X,beta)XXSXXX Phi; Suf1: Phi XRXXSXXX Phi; CaMKI: P hi XRXXS/TXXX Phi; where Phi is a hydrophobic residue (M, V, L, I or F ) and beta is a basic residue (R, K or H).