Molecular cloning and cell cycle-dependent expression of a novel gene that is homologous to cdc37.

A cDNA clone, termed N17, was isolated from a rat fibroblast 3Y1 cDNA library by a differential screening technique. The expression of the N17 gene was significantly increased in a variety of rapidly growing cells, including v-src-, v-Ha-ras-, or v-mos-transformed 3Y1 cells, when compared with parental 3Y1 cells. The N17 gene is present as a single copy in rat genome and is evolutionarily conserved among higher eukaryotes. The predicted open reading frame (ORF) encodes a polypeptide of 379 amino acids that exhibits a significant similarity with those of the cell cycle control protein Cdc37. The amount of N17 mRNA starts to be increased in the late G1 phase and the same level was retained until just before the G2/M phase. Taken together, these results suggest that N17 gene product may play a crucial role in the cell cycle control of 3Y1 cells.