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 -1104/+35 and -1104/-15 fragments cloned upstream of a luciferase reporter gene had very little constitutive activity and were not IL-1 beta responsive. In sharp contrast, a -1104/-234 fragment exhibited constitutive activity and was IL-1 beta responsive. The -1104/-234 fragment contains motifs that recognize Sp1, BCN-1, and ApoE-B1-AP1 DNA-binding activities in GEC nuclear extracts. Collectively, the results of this study suggest that multiple inducible transcription factors may regulate laminin gamma 1-chain gene promoter activity in GEC.
O'Neill
B C
BC
Department of Medicine, University of Washington, Seattle 98195, USA.
Suzuki
H
H
Loomis
W P
WP
Denisenko
O
O
Bomsztyk
K
K
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D003001:Cloning, Molecular; D015698:Genomic Library; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D007797:Laminin / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D016385:TATA Box; D014157:Transcription Factors / Q000378:metabolism*
D007797:Laminin; D014157:Transcription Factors; C089141:laminin gamma 1