Nucleotide sequence of the two rat cellular rasH genes

Area of Science:

• Molecular Biology
• Genetics
• Oncogenes

Background:

• The Harvey murine sarcoma virus ras gene (v-rasH) is a viral oncogene.
• Cellular ras genes (c-rasH) are proto-oncogenes involved in cell growth and differentiation.
• Understanding differences between viral and cellular ras proteins is crucial for cancer research.

Purpose of the Study:

• To determine the nucleotide sequence of the rat c-rasH-1 gene.
• To perform a partial sequence analysis of the rat c-rasH-2 gene.
• To compare these rat sequences with the Harvey murine sarcoma virus ras gene (v-rasH).

Main Methods:

• Nucleotide sequencing of the rat c-rasH-1 coding region.
• Partial nucleotide sequencing of the rat c-rasH-2 gene.
• Sequence comparison analysis between rat c-rasH-1, rat c-rasH-2, and v-rasH.

Main Results:

• The nucleotide sequence of the rat c-rasH-1 gene was determined.
• The p21 protein encoded by v-rasH differs from cellular c-rasH-1 p21 at amino acid positions 12 and 59.
• The rat c-rasH-2 gene appears to be a nonfunctional pseudogene, lacking introns and failing to transform NIH 3T3 cells.

Conclusions:

• Amino acid alterations at positions 12 and 59 in the viral p21 protein may contribute to its activation.
• The rat c-rasH-2 gene is likely a pseudogene due to sequence divergence and lack of functional elements.
• Comparative sequence analysis provides insights into ras gene evolution and oncogenic potential.