title: Expression, purification and characterization of the ubiquitous protein kinase C-related kinase 1.
abstract: The recently described protein kinase C-related kinase (PRK) family is comprised of at least three members: PRK1, PRK2 and PRK3. Here the expression, purification and characterization of the ubiquitously expressed isoform, PRK1, is described. The enzyme was expressed in COS 7 cells and subsequently purified to apparent homogeneity by sequential column chromatography. The purified PRK1 protein migrates as a single 120 kDa polypeptide on SDS/PAGE. It displays a substrate specificity that in part resembles that of protein kinase C (PKC); however, unlike PKC, it is not activated by any combination of phorbol esters, diacylglycerol and Ca2+. Nevertheless, it can be activated by limited proteolysis, indicating a negative regulatory role for the N-terminal domain(s). PRK1 is also activated by phospholipids. The physiological relevance of this activation is discussed.
authors.affiliation: Imperial Cancer Research Fund, London, U.K.
authors.forename: R H
authors.initials: RH
authors.lastname: Palmer
authors.forename: P J
authors.initials: PJ
authors.lastname: Parker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011493:Protein Kinase C / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: C061570:protein kinase N; D011493:Protein Kinase C