New PKCδ family members, PKCδIV, δV, δVI, and δVII are specifically expressed in mouse testis

We isolated and characterized four new PKC delta isoforms, PKC delta IV, delta V, delta VI, and delta VII, specifically expressed in the mouse testis. These isoforms possess neither V1 nor C2-like domains. Moreover, PKC delta VI and delta VII have a different last exon as their V5 domain. The transcription of PKC delta IV, delta V, delta VI, and delta VII is initiated from the same site in the upstream region of exon4 of the PKC delta gene. They are expressed exclusively in the testis in an age-dependent manner. PKC delta IV and delta V are expressed in spermatids with sperm maturation stage-specific manner, and that PKC delta VI and delta VII are expressed in spermatogonia and spermatocytes. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.