Question

what's the similarities and differences between v-ErbB protein and EGFR protein？And how does v-ErbB stay active？

Answer 1

Ans)

the ErbB group of proteins contain four receptor tyrosine kinases that are structurally related to the epidermal growth factor receptor/EGFR it is first the discovered member.the family includes EGFR & ErbB1,Neu & ErbB2, ErbB3, and ErbB4.gene symbol, ErbB is derived from the name of the viral oncogene,which these receptors are homologous. Insufficient ErbB signaling in humans is associated with the development of neurodegenerative diseases such as multiple sclerosis and Alzheimer's Disease while excessive ErbB signaling is associated with the development of a wide variety of types of solid tumor.both ErbB and EGFR are protein reseptor binding particles.ErbB is an oncogene and EGFR is a transmenbrane protein.the v-erbB transforming gene is derived by retroviral transduction from the gene c-erbB that encodes avian EGF receptor.transforming capacity of v-erbB appears by truncation of the receptor. In erythroid cells truncation of the N-terminal ligand binding domain is sufficient for transformation but for fibroblasts. removal of an additional C-terminal segment is required for transformation.the EGF receptor is subjected to complex regulatory controls like ligand activation, downregulation by internalization, autophosphorylation and transmodulation and autoregulation involving phosphorylation by kinase C.this is centered around the hypothesis that the transforming capacity of the truncated v-erbB gene product results from a loss in sensitivity to regulators and the consequent activation of protein kinase activity.EGFR is found on the surface of some normal cells and have a key role in cell growth.blocking EGFR will make cancer cells from not growing.sometimes EGFR inhibitors are used to treat cancer.