Cloning of rat laminin gamma 1-chain gene promoter reveals motifs for recognition of multiple transcription factors

We have previously shown that laminin gamma 1 (laminin B2)-chain mRNA levels increase in response to treatment of rat glomerular epithelial cells (GEC) with the cytokine interleukin-1 beta (IL-1 beta) [C. A. Richardson, K. L. Gordon, W. G. Couser, and K. Bomsztyk. Am. J. Physiol. 268 (Renal Fluid Electrolyte Physiol. 37): F273-F278, 1995]. IL-1 beta-induced increase in laminin gamma 1-chain gene expression is likely to be transcriptionally regulated. As the laminin gamma 1-chain gene promoter had not previously been cloned in the rat, we cloned the 5'-flanking region of this gene from a rat genomic library. Like the human and murine laminin gamma 1-chain gene promoters, the rat laminin gamma 1-chain gene fragment spanning from nucleotides -1104 to +109, relative to the start codon, is "GC" rich and lacks TATA or CAAT boxes. This rat laminin gamma 1-chain gene promoter region appears to contain at least two transcription initiation sites, i.e., position -169 and -234. In transient transfections in GEC, the...