POTATO PROTEIN-KINASE STCPK1 - A PUTATIVE EVOLUTIONARY LINK BETWEEN CDPKS AND CRKS

Calcium-dependent protein kinases (CDPKs) in plants are characterized by a four-domain structure including conserved sequences in the cataly tic domain, and in the C-terminal calmodulin-like domain. Based on thi s conservation we have PCR amplified and isolated a potato cDNA clone (StCPK1) from a library representing an early stage of tuber developme nt. DNA sequence analysis revealed that in the catalytic domain, StCPK 1 shares more homology with CDPK-related kinases than with CDPKs; howe ver, like CDPKs, it possesses canonical EF-hands at the calmodulin-lik e 3' end. StCPK1 exists in a few copies in the potato genome and is ab undantly expressed in the sepals of mature flowers. Floral expression of genes homologous to StCPK1 appears to be widespread in the family S olanaceae. (C) 1998 Elsevier Science B.V. All rights reserved.