Molecular cloning of two novel protein kinase genes from Arabidopsis thaliana

We have isolated two novel protein kinase genes, MHK and NAK, from the plant Arabidopsis thaliana by using low stringency hybridization with the catalytic domain of a putative plant receptor protein kinase. Sequence analysis of the cDNAs reveals that MHK is a member of the cdc2+ family of protein kinases and is particularly similar to the mak gene of rats; mak encodes a protein kinase that may play a role in spermatogenesis. NAK encodes a candidate protein kinase that is similar to the oncogenes met and abl. The homology that these two Arabidopsis genes share with other protein kinases suggests that they may play a role in the regulation of plant growth and development.