A domain of the alpha-subunit of rabbit phosphorylase kinase shows homologies with regions of rabbit alpha-tropomyosin, human EGF receptor, and the alpha chain of bovine S-100 protein.
Sequence comparison of the alpha-subunit of phosphorylase kinase with alpha-tropomyosin revealed 32% identity, and 49% similarity, between the region of alpha-tropomyosin coded by exon 5 and a 39 amino acid segment of the kinase subunit. A subsequence of the alpha-subunit segment and a sequence overlapping the same alpha-subunit region are homologous with: (a) a region of the cytoplasmic domain of EGF receptor (50% identity) and (b) a Ca(2+)-binding domain of the alpha chain of S-100 protein (50% identity) respectively. Statistical analysis shows that these homologies are significant. The biological implication of the above similarities is discussed.
Sotiroudis
T G
TG
Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Athens, Greece.
Geladopoulos
T P
TP
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D066246:ErbB Receptors / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D010764:Phosphorylase Kinase / Q000737:chemistry*; D011817:Rabbits; D009418:S100 Proteins / Q000737:chemistry*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014335:Tropomyosin / Q000737:chemistry*
D009418:S100 Proteins; D014335:Tropomyosin; D010764:Phosphorylase Kinase; D066246:ErbB Receptors