Dataset Information


N-terminal cleavage of proTGFalpha occurs at the cell surface by a TACE-independent activity.

ABSTRACT: ProTGFalpha (transforming growth factor alpha precursor) maturation and conversion into soluble TGFalpha is a complex process that involves three proteolytic steps. One, that occurs co-translationally, eliminates the signal sequence. Another, occurring at the juxta-membrane domain, solubilizes TGFalpha. A third cleavage removes the N-terminal extension of proTGFalpha. This latter step has been poorly studied, mainly because of the rapid kinetics of this cleavage. In the present study, we have designed a strategy to analyse several aspects regarding this N-terminal cleavage. In vivo treatment with the hydroxamate-based metalloprotease inhibitors BB3103 or TAPI-2 (tumour necrosis factor-alpha protease inhibitor 2) reversibly induced accumulation of forms of proTGFalpha that included the N-terminal extension. N-terminal shedding was rapid, and occurred at the cell surface. However, the machinery responsible for the N-terminal cleavage was inactive in other cellular sites, such as the endoplasmic reticulum. Experiments of proTGFalpha expression and maturation in cells deficient in TACE (tumour-necrosis-factor-alpha-converting enzyme) activity indicated that this protease was dispensable for N-terminal processing of proTGFalpha in vivo, but was required for regulated cleavage at the C-terminus. These findings indicate that TACE is not involved in N-terminal processing of proTGFalpha, and suggest differences in the machineries that control the cleavage at both ends of TGFalpha within its precursor.


PROVIDER: S-EPMC1184548 | BioStudies | 2005-01-01

SECONDARY ACCESSION(S): 10.1042/BJ20041128

REPOSITORIES: biostudies

Similar Datasets

2001-01-01 | S-EPMC1222008 | BioStudies
2004-01-01 | S-EPMC1223953 | BioStudies
2006-01-01 | S-EPMC6674310 | BioStudies
2004-01-01 | S-EPMC1223864 | BioStudies
2009-01-01 | S-EPMC2774824 | BioStudies
2002-01-01 | S-EPMC1222469 | BioStudies
2008-01-01 | S-EPMC2581452 | BioStudies
1000-01-01 | S-EPMC3113296 | BioStudies
1000-01-01 | S-EPMC3390988 | BioStudies
1998-01-01 | S-EPMC1219853 | BioStudies