Tissue‐specific subunit of the mouse cytosolic chaperonin‐containing TCP‐11

Abstract
We have cloned a novel Tcp‐1‐related mouse testis cDNA encoding a polypeptide of 531 amino acids which shares 81.2% identity with the ζ subunit of the mouse cytosolic chaperonin‐containing TCP‐1 (CCT). Immunoblot analysis of mouse testis CCT subunits separated by 2‐dimensional gel electrophoresis indicates that this novel gene, Cctz‐2, encodes a CCT subunit of M r 57 000 and pI 7.1. Cctz‐2 mRNA is detected only in testis whereas the other Cctz gene, Cctz‐1, is expressed in all tissues investigated. The CCTζ‐2 subunit may have specific functions in the folding of testicular proteins and for interactions with testicular molecular chaperones.