巨核细胞白血病1型(MKL1)是血清反响因子(SRF)共激活剂MKL家族的成员。在这里,我们已经确定了三种大鼠MKL1转录本:两种是小鼠MKL1转录本的同源物,全长MKL1(FLMKL1)和基本,SAP,和卷曲螺旋结构域(BSAC),第三个是小说抄本,MKL1-伸长的产率导数(MELODY)。这些大鼠MKL1转录物在睾丸和脑中具有最高水平的多种组织中差异表达。在大脑发育过程中,这些转录物显示不同的表达模式。FLMKL1转录物编码利用不同翻译起始位点的两种同种型。较长的形式具有三个肌动蛋白结合RPXXXEL(RPEL)基序和较短的形式,MKL1met只有两个RPEL图案。所有四种大鼠MKL1亚型,FLMKL1,BSAC,MKL1met和MELODY增加SRF介导的转录,但不是CREB介导的转录。因此,MKL1亚型的差异表达可能有助于在大脑发育过程中微调基因表达。
Megakaryoblastic leukemia 1 (MKL1) is a member of the MKL family of serum response factor (SRF) coactivators. Here we have identified three rat MKL1 transcripts: two are homologues of mouse MKL1 transcripts, full-length MKL1 (FLMKL1) and basic, SAP, and coiled-coil domains (BSAC), the third is a novel transcript, MKL1-elongated derivative of yield (MELODY). These rat MKL1 transcripts are differentially expressed in a wide variety of tissues with highest levels in testis and brain. During brain development, these transcripts display differential patterns of expression. The FLMKL1 transcript encodes two isoforms that utilize distinct translation start sites. The longer form possesses three actin-binding RPXXXEL (RPEL) motifs and the shorter form, MKL1met only has two RPEL motifs. All four rat MKL1 isoforms, FLMKL1, BSAC, MKL1met and MELODY increased SRF-mediated transcription, but not CREB-mediated transcription. Accordingly, the differential expression of MKL1 isoforms may help fine-tune gene expression during brain development.