Cloning, structure and mRNA expression of human Cctg, which encodes the chaperonin subunit CCTγ

Abstract

We describe the cloning, DNA sequence analysis and mRNA expression analysis of human Cctg (HsCctg), a gene that encodes the gamma-subunit of the eukaryotic cytosolic 'chaperonin-containing TCP-1' (CCT). Partial clones representing the 3' region of HsCctg cDNA were isolated from a human kidney cDNA library, and the missing 5' region was amplified directly from human kidney cDNA. The Cctg mRNA transcript is expressed in numerous human and mouse tissues and, like Tcp-1/Ccta, Cctg mRNA is expressed at higher levels in mouse testis when compared with kidney and brain. Southern-blot analysis has also revealed the Cctg gene to be highly conserved in mouse, rat, sheep and frog. The 1901 bp HsCctg cDNA has a coding region of 1635 bp and encodes a predicted 60 kDa protein (544 amino acids). The predicted HsCCT gamma amino acid sequence shares a high degree of sequence similarity with gamma-subunits from the mouse Mus musculus (98% similarity), the yeast Saccharomyces cerevisiae (75% similarity) and the protozoan Tetrahymena pyriformis (76% similarity) as well as with other members of the TF55/TCP-1 family, such as human TCP-1/CCT alpha (55% similarity) and TCP-20/CCT zeta (54% similarity). HsCCT gamma also shares conserved domains previously identified in the TF55/TCP-1 family of chaperonins and more distantly related chaperonins such as GroEL and Hsp60.

Cloning and subcellular localization of a human phosphatidylinositol 3-phosphate 5-kinase, PIKfyve/Fab1

“…The identification of further interacting partners of PIKfyve will no doubt provide more clues as to its intracellular functions. It is also worth considering that the chaperonin-like domain has been shown to have a high degree of similarity (N 55%) to TCP1-γ, a member of the TCP1 protein family (Walkley et al, 1996;Shisheva et al, 1999). This protein binds exclusively to actin and tubulin (Yaffe et al, 1992).…”

Gene expression changes in Schistosoma mansoni sporocysts induced by Biomphalaria glabrata embryonic cells

“…EA32 (398 bp) was identical to the EST (GenBank: AI395663) with an open reading frame of 81 residues encoding an unknown protein homologous to (41% identity) a Thermus aquaticus hypothetical protein (GenBank: P74897). Eg2 (329 bp) was identical to the EST (GenBank: AI974971) that encoded a 91 amino acid sequence of the S. mansoni chaperonin containing T-complex protein gamma subunit-like protein (SmTCP-1C) (57% identity with the human TCP-1C protein (GenBank: P49368, Walkley et al 1996). The two last sequences were found to correspond to new S. mansoni sequences.…”

Synthesis and function of membrane phosphoinositides in budding yeast, Saccharomyces cerevisiae

“…Fab1 also possesses a conserved FYVE domain (Fab1, YGL023, Vps27, and EEA1) ( Figure 9) in its NH 2 -terminal part, which serves as a PtdIns [3]P-specific binding motif [123]. Moreover, Fab1 contains another conserved region central in its primary sequence (Figure 9), which shares significant homology to a motif present in a subunit of the chaperonin containing T-complex, CCT-1 [330][331][332]. CCT-1 is an eight subunit chaperone with actin and tubulin-binding specificity that shares notable similarity with the GroEL chaperonin of E. coli [333,334].…”