Characterization of human SMARCE1r high-mobility-group protein.

The high-mobility-group (HMG) proteins are chromatin-associated proteins that are common to all higher organisms. They bind DNA in a sequence-specific or non-sequence-specific way to induce DNA bending, and regulate chromatin function and gene expression. Here we report the characterization of an HMG box-containing gene, designated human Smarce1r gene. It contained an open reading frame (ORF) encoding 317 amino acids and had 86% and 94% identity with the murine Smarce1r ORF at the nucleic acid and amino acid level, respectively. A putative nuclear localization signal, one HMG domain, and a coiled-coil domain were localized. A single transcript of 1.6 kb was ubiquitously expressed in various human tissues except for the fetal brain in which the transcript was barely detected. Western blot analysis revealed that human SMARCE1r was expressed in specific tissues such as colon and placenta. Subcellular fractionation, DNA-affinity column chromatography, and electrophoretic mobility shift assays showed that human SMARCE1r was associated with the nuclear matrix and that it possessed DNA binding activity, as expected.