Open AccessIdentification, expression and characterization of rat isoforms of the serum response factor (SRF) coactivator MKL1
Author(s) -
Ishikawa Mitsuru,
Shiota Jun,
Ishibashi Yuta,
Hakamata Tomoyuki,
Shoji Shizuku,
Fukuchi Mamoru,
Tsuda Masaaki,
Shirao Tomoaki,
Sekino Yuko,
Ohtsuka Toshihisa,
Baraban Jay M.,
Tabuchi Akiko
Publication year - 2013
Publication title -
febs open bio
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.718
H-Index - 31
ISSN - 2211-5463
DOI - 10.1016/j.fob.2013.09.001
Subject(s) - gene isoform , transcription factor , serum response factor , creb , coactivator , biology , messenger rna , gene expression , microbiology and biotechnology , gene , genetics
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.