Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 15 (15), 1781-6

Developmentally-regulated Expression of Murine K-ras Isoforms


Developmentally-regulated Expression of Murine K-ras Isoforms

S Pells et al. Oncogene.


The products (p21) of the three mammalian H-, N- and K-ras genes play important roles in intracellular signal transduction, linking membrane receptor kinases to the nuclear pathway through raf and mitogen activated protein kinase. They are involved in the regulation of proliferation and differentiation, and activating mutations of these genes are commonly associated with human cancers. Two p21 proteins are encoded by the K-ras gene (p21K-rasA and p21K-rasB) due to alternative splicing of the last exon. While the four p21ras proteins are highly homologous, their sequences diverge significantly at the C-termini, to which distinct biochemical and perhaps even functional differences may be ascribed. However, H-, N- and K-rasB appear to be ubiquitously expressed, with little evidence of tissue-specific or developmental regulation. In contrast, we now demonstrate that the expression of K-rasA is strikingly different. K-rasA is induced during differentiation of pluripotent embryonal stem cells in vitro. Its expression during early embryogenesis is limited temporally and spatially in a tissue-specific distribution which is largely maintained as an adult. This suggests a distinct biological role for p21K-rasA.

Similar articles

See all similar articles

Cited by 22 articles

See all "Cited by" articles

Publication types

LinkOut - more resources