IDENTIFICATION OF 21 NOVEL HUMAN PROTEIN-KINASES, INCLUDING 3 MEMBERSOF A FAMILY RELATED TO THE CELL-CYCLE REGULATOR NIMA OF ASPERGILLUS-NIDULANS

The nimA gene encodes a protein-serine/threonine kinase that is requir ed along with the p34cdc2 kinase for mitosis in Aspergillus nidulans. We have searched for human protein kinases that are related to the NIM A protein kinase using the polymerase chain reaction. Different pairs of degenerate oligonucleotides specific for conserved amino acid motif s in the catalytic domain of NIMA were used as primers in the polymera se chain reaction to amplify partial complementary DNAs (cDNAs) of pro tein kinases expressed in the promyelocytic leukemia cell line HL-60. Forty-one distinct cDNAs representing a broad spectrum of serine/threo nine- and tyrosine-specific protein kinases were identified, and the s equences for 21 of these protein kinases were found to be unique. Thre e of these cDNAs represent a family of protein kinases whose members a re related to NIMA and the murine nimA-related protein kinase Nek1. We discuss the success of this polymerase chain reaction approach with r espect to the use of multiple primer pairs, the influence of primer de generacy, and the tolerance of cDNA amplification to mismatches betwee n primers and template mRNA.