Myocardin regulates exon usage in smooth muscle cells through induction of splicing regulatory factors.
Stenkula, Karin G
Smith, Christopher W J
Fisher, Steven A
JournalCellular and Molecular Life Sciences : CMLS
MetadataShow full item record
AbstractDifferentiation of smooth muscle cells (SMCs) depends on serum response factor (SRF) and its co-activator myocardin (MYOCD). The role of MYOCD for the SMC program of gene transcription is well established. In contrast, the role of MYOCD in control of SMC-specific alternative exon usage, including exon splicing, has not been explored. In the current work we identified four splicing factors (MBNL1, RBPMS, RBPMS2, and RBFOX2) that correlate with MYOCD across human SMC tissues. Forced expression of MYOCD family members in human coronary artery SMCs in vitro upregulated expression of these splicing factors. For global profiling of transcript diversity, we performed RNA-sequencing after MYOCD transduction. We analyzed alternative transcripts with three different methods. Exon-based analysis identified 1637 features with differential exon usage. For example, usage of 3´ exons in MYLK that encode telokin increased relative to 5´ exons, as did the 17 kDa telokin to 130 kDa MYLK protein ratio. Dedicated event-based analysis identified 239 MYOCD-driven splicing events. Events involving MBNL1, MCAM, and ACTN1 were among the most prominent, and this was confirmed using variant-specific PCR analyses. In support of a role for RBPMS and RBFOX2 in MYOCD-driven splicing we found enrichment of their binding motifs around differentially spliced exons. Moreover, knockdown of either RBPMS or RBFOX2 antagonized splicing events stimulated by MYOCD, including those involving ACTN1, VCL, and MBNL1. Supporting an in vivo role of MYOCD-SRF-driven splicing, we demonstrate altered Rbpms expression and splicing in inducible and SMC-specific Srf knockout mice. We conclude that MYOCD-SRF, in part via RBPMS and RBFOX2, induce a program of differential exon usage and alternative splicing as part of the broader program of SMC differentiation.
Rights/Terms© 2022. The Author(s).
Identifier to cite or link to this itemhttp://hdl.handle.net/10713/19513
- Expression and functional activity of four myocardin isoforms.
- Authors: Imamura M, Long X, Nanda V, Miano JM
- Issue date: 2010 Sep 15
- Coronary Disease-Associated Gene TCF21 Inhibits Smooth Muscle Cell Differentiation by Blocking the Myocardin-Serum Response Factor Pathway.
- Authors: Nagao M, Lyu Q, Zhao Q, Wirka RC, Bagga J, Nguyen T, Cheng P, Kim JB, Pjanic M, Miano JM, Quertermous T
- Issue date: 2020 Feb 14
- Identification of RBPMS as a mammalian smooth muscle master splicing regulator via proximity of its gene with super-enhancers.
- Authors: Nakagaki-Silva EE, Gooding C, Llorian M, Jacob AG, Richards F, Buckroyd A, Sinha S, Smith CWJ
- Issue date: 2019 Jul 8
- YY1 directly interacts with myocardin to repress the triad myocardin/SRF/CArG box-mediated smooth muscle gene transcription during smooth muscle phenotypic modulation.
- Authors: Zheng JP, He X, Liu F, Yin S, Wu S, Yang M, Zhao J, Dai X, Jiang H, Yu L, Yin Q, Ju D, Li C, Lipovich L, Xie Y, Zhang K, Li HJ, Zhou J, Li L
- Issue date: 2020 Dec 11
- Identification of a Klf4-dependent upstream repressor region mediating transcriptional regulation of the myocardin gene in human smooth muscle cells.
- Authors: Turner EC, Huang CL, Govindarajan K, Caplice NM
- Issue date: 2013 Nov