Identification, expression and characterization of rat isoforms of the serum response factor (SRF) coactivator MKL1

Mitsuru Ishikawa, Jun Shiota, Yuta Ishibashi, Tomoyuki Hakamata, Shizuku Shoji, Mamoru Fukuchi, Masaaki Tsuda, Tomoaki Shirao, Yuko Sekino, Toshihisa Ohtsuka, Jay M. Baraban, Akiko Tabuchi

Research output: Contribution to journalArticlepeer-review


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.

Original languageEnglish (US)
Pages (from-to)387-393
Number of pages7
JournalFEBS Open Bio
StatePublished - 2013


  • Alternative promoter
  • Megakaryoblastic leukemia
  • Serum response factor
  • Transcript
  • Transcriptional coactivator

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)


Dive into the research topics of 'Identification, expression and characterization of rat isoforms of the serum response factor (SRF) coactivator MKL1'. Together they form a unique fingerprint.

Cite this