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Adrenocortical zonation factor 1 is a novel matricellular protein promoting integrin‐mediated adhesion of adrenocortical and vascular smooth muscle cells
Author(s) -
Li Dan,
Mukai Kuniaki,
Suzuki Tsuneharu,
Suzuki Reiko,
Yamashita Shuji,
Mitani Fumiko,
Suematsu Makoto
Publication year - 2007
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2007.05786.x
Subject(s) - integrin , matricellular protein , microbiology and biotechnology , cell adhesion , adhesion , vascular smooth muscle , alpha (finance) , chemistry , extracellular matrix , biology , cell , medicine , smooth muscle , endocrinology , biochemistry , organic chemistry , construct validity , nursing , patient satisfaction
Expression of a previously cloned secretory protein named adrenocortical zonation factor 1 (AZ‐1, also called Tin‐ag‐RP or lipocalin 7) is tightly linked with the zonal differentiation of adrenocortical cells. It is also present in vascular smooth muscle (VSM), although its function has remained unknown. In this study, the location of AZ‐1 was specified to the basal laminae along adrenocortical sinusoidal capillaries and surrounding VSM cells in the arterial system, consistent with the fact that AZ‐1 was extractable under denaturing conditions as a 52 kDa polypeptide. Purified recombinant AZ‐1 exhibited abilities to bind to fibronectins via the first type III repeat (anastellin) and to collagens with affinities in submicromolar ranges. AZ‐1 immobilized on substratum or bound to collagens or anastellin promoted adhesion and spreading of adrenocortical cells. Although VSM cells spread on AZ‐1 slowly, AZ‐1 bound to anastellin facilitated the spreading. The adhesion activity of AZ‐1 was mediated by a subset of integrins, including α 1 β 1 , α 2 β 1 , and α 5 β 1 , in a cell type‐specific manner. Collectively with the putative role of AZ‐1 in the adrenocortical zonation, we propose that AZ‐1 potentially regulates functions of adrenocortical and VSM cells by modulating cell–matrix interactions.