| abstract |
Transcriptionally regulated growth-response genes play a pivotal role in the determination o a cell's fate. p53 is known to transcriptionally regulate genes important in regulating cell growth potential. Using differential RT-PCR analysis of rat embryo fibroblast cells containing a temperature-sensitive p53 allele, we were able to isolate several transcripts upregulated specifically in cells harboring the wild-type p53 protein. Two of these genes, SM20 and microsomal epoxide hydrolase (mEH), are previously described genes. Two previously uncharacterized cDNA's, cell growth regulatory (CGR) genes CGR11 and CGR19, were isolated. The predicted amino acid sequences of these novel proteins contain known motifs; EF-hand domains (CGR11) and a ring-finger domain (CGR19), are suggestive of function. CGR11 and CGR19 appear to be primary response genes expressed at 0.05 % and 0.01 % of the total mRNA in wild-type p53 cells. Both CGR11 and CGR19 as well as SM20 and mEH, are able to inhibit growth of several cell lines. |