Open AccessCharacterization of a secreted glycoprotein of the immunoglobulin superfamily inducible by mitogen and oncogene
Author(s) -
WERENSKIOLD Anne Katrin
Publication year - 1992
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1992.tb16726.x
Subject(s) - tunicamycin , glycoprotein , glycosylation , microbiology and biotechnology , polyclonal antibodies , vaccinia , biology , antiserum , virus , gene , orthopoxvirus , recombinant dna , antibody , biochemistry , chemistry , virology , unfolded protein response , immunology
The T1 gene is transiently activated by the Ha‐ ras (EJ) or v‐ mos oncoproteins and by mitogens in NIH3T3 fibroblasts. Its primary gene product of 337 amino acids (38 kDa) undergoes extensive post‐translational modification. For biochemical analysis, the T1 gene product was over‐expressed in a vaccinia virus system. Cells infected with a recombinant T1‐vaccinia virus produce and secrete multiple proteins of 60–70 kDa which react with polyclonal antisera raised against two T1‐specific peptides. Two lines of evidence suggest that the apparent size heterogeneity of the T1 protein is due to a variable carbohydrate content of 40–50% of the total molecular mass. First, in the presence of an inhibitor of N ‐glycosylation (tunicamycin), a single 38‐kDa protein is detected by the antisera in the cells infected with T1‐vaccinia virus. Second, glycosidase digestions show that T1 protein maturation involves glycosylation and sialylation. These post‐translational modification steps appear to be similar in different types of cells.