| Literature DB >> 14521955 |
Sanjida Ahmed1, Kazuhiro Yamamoto, Yuichiro Sato, Takashi Ogawa, Andreas Herrmann, Shouichi Higashi, Kaoru Miyazaki.
Abstract
Insulin-like growth factor (IGF) binding protein-related protein-1 (IGFBP-rP1) was previously identified as tumor-derived adhesion factor (TAF) secreted from human bladder carcinoma cells. It exhibits growth-stimulatory activity in synergy with insulin or IGFs. In the present study, we found that IGFBP-rP1 was proteolytically cleaved to a two-chain form. The cleavage sequence suggested that a trypsin-like serine proteinase may be responsible for the processing. The cleavage of IGFBP-rP1 led to an almost complete loss of both insulin/IGF-1-binding activity and insulin/IGF-1-dependent growth-stimulatory activity. On the other hand, the cell attachment activity of IGFBP-rP1 was markedly increased by the proteolytic processing. Syndecan-1 was thought to be a cell surface receptor for both intact and cleaved IGFBP-rP1 forms. Although the proteolytic cleavage of IGFBP-rP1 decreased its heparin-binding activity, the cleaved form could bind syndecan-1 efficiently. Thus the proteolytic processing of IGFBP-rP1 seems to modulate its insulin/IGF-dependent and -independent biological functions.Entities:
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Year: 2003 PMID： 14521955 DOI： 10.1016/j.bbrc.2003.09.058
Source DB: PubMed Journal: Biochem Biophys Res Commun ISSN： 0006-291X Impact factor: 3.575