Biosynthesis of the epidermal growth factor receptor in A431 cells.
AUTOR(ES)
Mayes, E L
RESUMO
A monoclonal antibody R1 against the human epidermal growth factor receptor has been used to study biosynthesis in the carcinoma cell line A431. Two glycoproteins of apparent mol. wts. 95 000 and 160 000 were immunoprecipitated from cells labelled for short times with [35S]methionine or [3H]mannose. Pulse-chase studies show the 160 000 mol. wt. glycoprotein to be a precursor of the 175 000 mol. wt. receptor, but do not establish a precursor role for the 95 000 mol. wt. glycoprotein. Limited proteolysis, peptide mapping, endoglycosidase digestion and the use of monensin and tunicamycin show that the 95 000 mol. wt. glycoprotein is structurally related to the 160 000 mol. wt. glycoprotein and that both glycoproteins have approximately 22 000 - 28 000 mol. wt. of oligosaccharide side chains. Monensin blocks conversion of the 160 000 to the 175 000 mol. wt. mature receptor, a process which involves complexing several of its N-linked oligosaccharide chains. Pulse-chase studies showed that an immunoprecipitable polypeptide of 115 000 mol. wt., or 95 000 mol. wt., in the presence of monensin, was secreted into the medium at late chase times. The possible mechanisms for the origins of all the receptor-related polypeptides are discussed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=557382Documentos Relacionados
- Aspects of the metabolism of the epidermal growth factor receptor in A431 human epidermoid carcinoma cells.
- Kinetics and regulation of the tyrosine phosphorylation of epidermal growth factor receptor in intact A431 cells.
- Blood group-active carbohydrate chains on the receptor for epidermal growth factor of A431 cells.
- Down-regulation of epidermal growth factor receptor correlates with plasminogen activator activity in human A431 epidermoid carcinoma cells.
- Epidermal growth factor inhibits the synthesis of the nuclear protein cyclin in A431 human carcinoma cells.