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A gene activated by growth factors is related to the oncogene v-jun
Abstract:
We have recently identified by cDNA cloning a set of genes that are rapidly activated in cultured mouse cells by protein growth factors. Here we report that the nucleotide sequence of a cDNA (clone 465) derived from one of these immediate early genes (hereafter called jun-B) encodes a protein homologous to that encoded by the avian sarcoma virus 17 oncogene v-jun. Homology between the jun-B and v-jun proteins is in two regions: one near the N terminus and the other at the C terminus. The latter sequence was shown by Vogt et al. [Vogt, P. K., Bos, T. J. & Doolittle, R. F. (1987) Proc. Natl. Acad. Sci. USA 84, 3316-3319] to have regions of sequence similarity to the DNA-binding domain of the yeast transcriptional regulatory protein GCN4 and to the oncogenic protein fos. Southern blots of human, mouse, and chicken DNA demonstrate that jun-B and c-jun are different genes and that there may be other vertebrate genes related to jun-B and c-jun. These findings suggest that there is a jun family of genes encoding related transcriptional regulatory proteins. The jun-B protein, and perhaps other members of the jun family, may play a role in regulating the genomic response to growth factors.
Insights
Researchers discovered the jun-B gene, which encodes a protein similar to the v-jun oncogene. This finding suggests a new family of jun genes involved in the cellular response to growth factors.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Protein growth factors rapidly activate specific genes in cultured mouse cells.
- Immediate early genes play a crucial role in cellular responses to external stimuli.
Purpose of the Study:
- To identify and characterize novel genes rapidly activated by protein growth factors.
- To investigate the sequence homology and evolutionary relationship of a newly identified gene, jun-B.
Main Methods:
- cDNA cloning to identify activated genes.
- Nucleotide sequencing of cDNA clone 465 (jun-B).
- Southern blot analysis of DNA from different species (human, mouse, chicken).
Main Results:
- The jun-B gene encodes a protein homologous to the v-jun oncogene, with conserved regions near the N and C termini.
- The C-terminal region shows sequence similarity to DNA-binding domains of yeast GCN4 and the oncogenic protein fos.
- jun-B and c-jun are distinct genes, and related genes exist in vertebrates, suggesting a jun gene family.
Conclusions:
- A jun gene family encoding related transcriptional regulatory proteins has been identified.
- The jun-B protein may be involved in regulating the genomic response to growth factors.