Protein Kinase D1 (PKD1)

By screening a placenta cDNA library using a PCR fragment derived from the second conserved domain within the catalytic site of ser/thr protein kinases, Johannes et al. obtained a full-length cDNA encoding PKC-mu. The deduced 912-amino acid PRKCM protein has a calculated molecular mass of 102 kD. PRKCM has 2 characteristic cysteine-rich repeats, which are conserved among nearly all members of the PKC family, a conserved ATP-binding consensus sequence in the kinase domain, and the invariate aspartate essential for kinase activity. Northern blot analysis detected a single PRKCM transcript of 3.8 kb at low, constitutive levels in all tissues examined. The authors verified PRKCM kinase activity by transfection of a PRKCM expression vector and detecting changes in protein phosphorylation patterns by Western blot analysis.