Structure of the C2 domain from novel protein kinase Cepsilon. A membrane binding model for Ca(2+)-independent C2 domains.

Protein kinase Cepsilon (PKCepsilon) is a member of the novel PKCs which are activated by acidic phospholipids, diacylglycerol and phorbol esters, but lack the calcium dependence of classical PKC isotypes. The crystal structures of the C2 domain of PKCepsilon, crystallized both in the absence and in the presence of the two acidic phospholipids, 1,2-dicaproyl-sn-phosphatidyl-l-serine (DCPS) and 1,2-dicaproyl-sn-phosphatidic acid (DCPA), have now been determined at 2.1, 1.7 and 2.8 A resolution, respectively. The central feature of the PKCepsilon-C2 domain structure is an eight-stranded, antiparallel, beta-sandwich with a type II topology similar to that of the C2 domains from phospholipase C and from novel PKCdelta. Despite the similar topology, important differences are found between the structures of C2 domains from PKCs delta and epsilon, suggesting they be considered as different PKC subclasses. Site-directed mutagenesis experiments and structural changes in the PKCepsilon-C2 domain from crystals with DCPS or DCPA indicate, though phospholipids were not visible in these structures, that loops joining strands beta1-beta2 and beta5-beta6 participate in the binding to anionic membranes. The different behavior in membrane-binding and activation between PKCepsilon and classical PKCs appears to originate in localized structural changes, which include a major reorganization of the region corresponding to the calcium binding pocket in classical PKCs. A mechanism is proposed for the interaction of the PKCepsilon-C2 domain with model membranes that retains basic features of the docking of C2 domains from classical, calcium-dependent, PKCs.

Ochoa WF ，Garcia-Garcia J ，Fita I ，Corbalan-Garcia S ，Verdaguer N ，Gomez-Fernandez JC ... -  《JOURNAL OF MOLECULAR BIOLOGY》

Additional binding sites for anionic phospholipids and calcium ions in the crystal structures of complexes of the C2 domain of protein kinase calpha.

Ochoa WF ，Corbalán-Garcia S ，Eritja R ，Rodríguez-Alfaro JA ，Gómez-Fernández JC ，Fita I ，Verdaguer N ... -  《JOURNAL OF MOLECULAR BIOLOGY》

Ca(2+) bridges the C2 membrane-binding domain of protein kinase Calpha directly to phosphatidylserine.

Verdaguer N ，Corbalan-Garcia S ，Ochoa WF ，Fita I ，Gómez-Fernández JC ... -  《-》

Characterization of the membrane binding mode of the C2 domain of PKC epsilon.

Corbalán-Garcia S ，Sánchez-Carrillo S ，García-García J ，Gómez-Fernández JC ... -  《BIOCHEMISTRY》

Retinoic acid binds to the C2-domain of protein kinase C(alpha).

Ochoa WF ，Torrecillas A ，Fita I ，Verdaguer N ，Corbalán-García S ，Gomez-Fernandez JC ... -  《BIOCHEMISTRY》