Molecular cloning and characterization of protein kinase D: a target for diacylglycerol and phorbol esters with a distinctive catalytic domain.

AM Valverde, J Sinnett-Smith… - Proceedings of the …, 1994 - National Acad Sciences
AM Valverde, J Sinnett-Smith, J Van Lint, E Rozengurt
Proceedings of the National Academy of Sciences, 1994National Acad Sciences
A serine/threonine protein kinase that binds phorbol esters and diacylglycerol (named
protein kinase D, PKD) has been identified. PKD contains membrane localization signals
and a cysteine-rich repeat sequence homologous to that seen in the regulatory domain of
protein kinase C (PKC). A bacterially expressed N-terminal domain of PKD exhibited high-
affinity phorbol ester binding activity (Kd= 35 nM). The diacylglycerol analog 1-oleoyl-2-
acetylglycerol inhibited phorbol ester binding in a dose-dependent manner. The catalytic …
A serine/threonine protein kinase that binds phorbol esters and diacylglycerol (named protein kinase D, PKD) has been identified. PKD contains membrane localization signals and a cysteine-rich repeat sequence homologous to that seen in the regulatory domain of protein kinase C (PKC). A bacterially expressed N-terminal domain of PKD exhibited high-affinity phorbol ester binding activity (Kd = 35 nM). The diacylglycerol analog 1-oleoyl-2-acetylglycerol inhibited phorbol ester binding in a dose-dependent manner. The catalytic domain of PKD contains all characteristic sequence motifs of serine protein kinases but shows only a low degree of sequence similarity to PKCs. The highest identity is with the catalytic domain of myosin light-chain kinase from Dictyostelium (41%). The bacterially expressed catalytic domain of PKD efficiently phosphorylated the exogenous peptide substrate syntide 2 in serine but did not catalyze significant phosphorylation of a variety of other substrates used by PKCs and other major second messenger regulated kinases. PKD may be an unusual component in the transduction of diacylglycerol and phorbol ester signals.
National Acad Sciences