SMAR1, a novel, alternatively spliced gene product, binds the Scaffold/Matrix-associated region at the T cell receptor beta locus.
Rearrangement and expression of the T cell receptor beta gene are critical events for early T lymphocyte development. To characterize cis-regulatory elements and their associated trans-factors that mediate these events, we have previously identified a nuclear matrix/scaffold-associated region, referred to as MARbeta, 400 bp upstream of the Ebeta enhancer. Electrophoretic mobility shift assay showed that two known MAR-binding proteins, SATB1 and Cux, bind MARbeta. In this article, we report the identification of a novel MAR-binding protein, named SMAR1, that also binds MARbeta. SMAR1 shares homology with SATB1 and Cux in the MAR-binding domain/Cut repeat and also with the tetramerization domain of a B cell-specific MAR-binding protein, Bright. The binding of GST-SMAR1 fusion protein to MARbeta is inhibited by the presence of an excess amount of MAR-containing DNA from the immunoglobulin kappa locus. Smar1 transcripts are most abundant in the thymus and are alternatively spliced. The smar1 gene maps to the distal portion of mouse chromosome 8 at a distance of 111.8 cM.
Chattopadhyay
S
S
National Center for Cell Science, Ganeshkhind, Maharastra, Pune-411007, India.
Kaul
R
R
Charest
A
A
Housman
D
D
Chen
J
J
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins; D002460:Cell Line; D002874:Chromosome Mapping; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D019674:Genes, T-Cell Receptor beta / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009115:Muridae; D015530:Nuclear Matrix / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D012313:RNA / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014158:Transcription, Genetic
C417914:BANP protein, human; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012313:RNA