Inducible transcriptional activity of the bcn-1 element from the
laminin [gamma]1 chain gene promoter in renal and non-renal
cells..
Suzuki, Hideaki, Oleg N. Denisenko, Yu Suzuki, Daniel S. Schullery,
and Karol Bomsztyk.
Department of Medicine, University of Washington, Seattle, WA
98195
APStracts 5:0128F, 1998.
Laminin is a major component of the extracellular matrix (ECM) whose
expression is regulated by growth factors. The laminin [gamma]1 chain
promoter contains a newly identified transcriptional element denoted
bcn-1 that is both both active and inducible in mesangial cells. In
this study, we explored activation of the bcn-1 element in other
renal and non-renal cells. Treatment of rat glomerular epithelial
cells (GEC) with phorbol 12-myristate 13-acetate (PMA) increased
activity of the bcn-1 transcriptional element, within the context of
the native laminin [gamma]1 chain promoter or when cloned upstream of
a heterologous promoter. Treatment of GEC with PMA induced nuclear
DNA-binding activity, BCN-1, which was recognized by the bcn-1 motif
in a gel shift assay. These results provide evidence that the bcn-1
motif and its cognate BCN-1 factor(s) may regulate transcription of
the laminin [gamma]1 chain in GEC. The bcn-1 element and its cognate
BCN-1 DNA-binding activity was also inducible in monkey kidney COS-7
and in human T cell Jurkat lines. SDS-PAGE of in situ UV-crosslinked
nucleoproteins from GEC, COS and Jurkat cells revealed one major 110
-115 kDa adduct in all three cell lines. These results demonstrate
that the bcn-1 element is active in renal and non-renal cells from
different mammalian species where the same protein contributes to the
inducible BCN-1 DNA-binding activity.
Received 14 January 1998; accepted in final form 22 July 1998.
APS Manuscript Number F12-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 21 September 1998