Interaction of Rat Cdc37-Related Protein with Retinoblastoma Gene Product

Abstract

By using in vitro binding assays and the yeast two-hybrid system, we have found that a full-length rat Cdc37-related protein (RCdc37) could associate specifically with the retinoblastoma susceptibility gene product (pRB). A series of GST-RCdc37 deletion mutants was constructed to define the amino acid sequence required for the interaction with pRB. A GST-RCdc37 (-20 approximately 229) possessed an activity to associate with pRB, whereas GST-RCdc37 (-20 approximately 165) lost its activity, indicating that the amino acid sequence between 166 and 229 of RCdc37 was essential for the association with pRB. Interestingly, there exists a highly conserved pRB-binding motif (LXCXE; X = any amino acid) that is essential for pRB binding of SV40 large T antigen, E1A, and E7 proteins. A similar experiment using a pRB deletion mutant revealed that the carboxy-terminal portion of pRB was required for binding to RCdc37.

Organization of the Chick CDC37 Gene

“…CDC37 and pRB also bind specifically to each other, suggesting that CDC37-pRB-DNA interactions may be involved in cell cycle regulation (19).…”

Database of mutations within the adenovirus 5 E1A oncogene

“…Analyses of the phenotypes of a battery of mutants have established strong correlations between various E1A activities and identified important links between E1A function and its association with cellular factors (1)(2)(3)(4)(5) independently, and sometimes redundantly, to provoke changes in cell regulation (1,5). Intriguingly, domains homologous to those first identified in E1A by mutational analysis have been found in a number of other viral (13)(14)(15) and cellular (16)(17)(18)(19)(20)(21) proteins, providing immediate insight into their mechanism of action.…”

Genomic organization and the promoter region of the round-spotted pufferfish (Tetraodon fluviatilis) CDC37 gene

“…The comparison also reveals the presence of two hyaluronan-binding motifs [19] (amino acid residues 158^168 and 263^273 in Fig. 2) and the pRB-binding motif (LVCEE) [20] that are conserved among vertebrate species. Other motifs, such as one putative tyrosine phosphorylation site (WDDSQKY) and a potential serine phosphorylation site (IEVSDD) by casein kinase II are also found in pu¡er¢sh Cdc37 protein.…”