scholarly journals Post-transcriptional regulation of MRTF-A by miRNAs during myogenic differentiation of myoblasts

2020 ◽  
Vol 48 (16) ◽  
pp. 8927-8942
Author(s):  
Ingo Holstein ◽  
Anurag Kumar Singh ◽  
Falk Pohl ◽  
Danny Misiak ◽  
Juliane Braun ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Mirna Expression ◽  
Binding Sites ◽  
Serum Response Factor ◽  
Myogenic Differentiation ◽  
Affinity Purification ◽  
Protein Abundance ◽  
Related Transcription Factor ◽  
Post Transcriptional Regulation ◽  
Serum Response

Abstract The differentiation and regeneration of skeletal muscle from myoblasts to myotubes involves myogenic transcription factors, such as myocardin-related transcription factor A (MRTF-A) and serum response factor (SRF). In addition, post-transcriptional regulation by miRNAs is required during myogenesis. Here, we provide evidence for novel mechanisms regulating MRTF-A during myogenic differentiation. Endogenous MRTF-A protein abundance and activity decreased during C2C12 differentiation, which was attributable to miRNA-directed inhibition. Conversely, overexpression of MRTF-A impaired differentiation and myosin expression. Applying miRNA trapping by RNA affinity purification (miTRAP), we identified miRNAs which directly regulate MRTF-A via its 3′UTR, including miR-1a-3p, miR-206-3p, miR-24-3p and miR-486-5p. These miRNAs were upregulated during differentiation and specifically recruited to the 3′UTR of MRTF-A. Concomitantly, Ago2 recruitment to the MRTF-A 3′UTR was considerably increased, whereas Dicer1 depletion or 3′UTR deletion elevated MRTF-A and inhibited differentiation. MRTF-A protein expression was inhibited by ectopic miRNA expression in murine C2C12 and primary human myoblasts. 3′UTR reporter activity diminished upon differentiation or miRNA expression, whereas deletion of the predicted binding sites reversed these effects. Furthermore, TGF-β abolished MRTF-A reduction and decreased miR-486-5p expression. Our findings implicate miR-24-3p and miR-486-5p in the repression of MRTF-A and suggest a complex network of transcriptional and post-transcriptional mechanisms regulating myogenesis.

scholarly journals Enhancement of mDia2 activity by Rho-kinase-dependent phosphorylation of the diaphanous autoregulatory domain

2011 ◽  
Vol 439 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Dean P. Staus ◽  
Joan M. Taylor ◽  
Christopher P. Mack
Keyword(s):  
Smooth Muscle ◽  
Actin Polymerization ◽  
Serum Response Factor ◽  
Rho Kinase ◽  
Specific Gene ◽  
Related Transcription Factor ◽  
Inhibitory Domain ◽  
Serum Response ◽  
Acidic Region ◽  
Basic Region

It is clear that RhoA activates the DRF (diaphanous-related formin) mDia2 by disrupting the molecular interaction between the DAD (diaphanous autoregulatory domain) and the DID (diaphanous inhibitory domain). Previous studies indicate that a basic motif within the DAD contributes to mDia2 auto-inhibition, and results shown in the present study suggest these residues bind a conserved acidic region within the DID. Furthermore, we demonstrate that mDia2 is phosphorylated by ROCK (Rho-kinase) at two conserved residues (Thr1061 and Ser1070) just C-terminal to the DAD basic region. Phosphomimetic mutations to these residues in the context of the full-length molecule enhanced mDia2 activity as measured by increased actin polymerization, SRF (serum response factor)-dependent smooth muscle-specific gene transcription, and nuclear localization of myocardin-related transcription factor B. Biochemical and functional data indicate that the T1061E/S1070E mutation significantly inhibited the ability of DAD to interact with DID and enhanced mDia2 activation by RhoA. Taken together, the results of the present study indicate that ROCK-dependent phosphorylation of the mDia2 DAD is an important determinant of mDia2 activity and that this signalling mechanism affects actin polymerization and smooth muscle cell-specific gene expression.

The correlations of the function and positional distribution of the cis-elements CArG around the TSS in the genes of Mus musculus

Genome ◽  
2009 ◽  
Vol 52 (3) ◽  
pp. 217-221 ◽  
Author(s):  
Xia Shen ◽  
Bruce Walsh ◽  
Jing J. Li ◽  
Hong X. Pang ◽  
Wen J. Wang ◽  
...  
Keyword(s):  
Binding Sites ◽  
Copy Number ◽  
Serum Response Factor ◽  
Sequence Data ◽  
Positional Distribution ◽  
Cis Elements ◽  
Transcription Start ◽  
Data Set ◽  
Control Set ◽  
Serum Response

While many studies of cis-elements CArG bound by serum response factor (SRF) are in progress, little is known about the positional distribution of the functional CArG elements around the transcription start site (TSS) of genes that they influence. We use a validated CArG data set to calculate the distance distribution of functional CArG elements around the TSS. Distances between adjacent CArGs were also analyzed. We compare these distributions with those derived using a control set of randomly selected CArGs (that were not experimentally validated for function). Our results show that most functional CArG elements (108 of 152, 71%) exist upstream of the annotated TSS, with copy number increasing as one moves closer to the TSS. Moreover, the average number of the CArG elements in the CArG-containing genes is significantly more than that in the control genes. Our study extends earlier bioinformatic analyses of functional CArG elements and provides an application of comparative sequence data to the identification of transcription factor binding sites.

scholarly journals Myocardin-Related Transcription Factor A Activation by Competition with WH2 Domain Proteins for Actin Binding

2016 ◽  
Vol 36 (10) ◽  
pp. 1526-1539 ◽  
Author(s):  
Julia Weissbach ◽  
Franziska Schikora ◽  
Anja Weber ◽  
Michael Kessels ◽  
Guido Posern
Keyword(s):  
Serum Response Factor ◽  
De Novo ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Serum Stimulation ◽  
Competitive Mechanism ◽  
Related Transcription Factor ◽  
Simultaneous Inhibition ◽  
Serum Response

The myocardin-related transcription factors (MRTFs) are coactivators of serum response factor (SRF)-mediated gene expression. Activation of MRTF-A occurs in response to alterations in actin dynamics and critically requires the dissociation of repressive G-actin–MRTF-A complexes. However, the mechanism leading to the release of MRTF-A remains unclear. Here we show that WH2 domains compete directly with MRTF-A for actin binding. Actin nucleation-promoting factors, such as N-WASP and WAVE2, as well as isolated WH2 domains, including those of Spire2 and Cobl, activate MRTF-A independently of changes in actin dynamics. Simultaneous inhibition of Arp2-Arp3 or mutation of the CA region only partially reduces MRTF-A activation by N-WASP and WAVE2. Recombinant WH2 domains and the RPEL domain of MRTF-A bind mutually exclusively to cellular and purified G-actinin vitro. The competition by different WH2 domains correlates with MRTF-SRF activation. Following serum stimulation, nonpolymerizable actin dissociates from MRTF-A, andde novoformation of the G-actin–RPEL complex is impaired by a transferable factor. Our work demonstrates that WH2 domains activate MRTF-A and contribute to target gene regulation by a competitive mechanism, independently of their role in actin filament formation.

scholarly journals Serum response factor binding sites differ in three human cell types

2007 ◽  
Vol 17 (2) ◽  
pp. 136-144 ◽  
Author(s):  
S. J. Cooper ◽  
N. D. Trinklein ◽  
L. Nguyen ◽  
R. M. Myers
Keyword(s):  
Human Cell ◽  
Binding Sites ◽  
Serum Response Factor ◽  
Cell Types ◽  
Response Factor ◽  
Factor Binding ◽  
Serum Response

scholarly journals Fixed differences in the 3′UTR of buffalo PRNP gene provide binding sites for miRNAs post-transcriptional regulation

Oncotarget ◽  
2017 ◽  
Vol 8 (28) ◽  
pp. 46006-46019 ◽  
Author(s):  
Hui Zhao ◽  
Siqi Wang ◽  
Lixia Guo ◽  
Yanli Du ◽  
Linlin Liu ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Binding Sites ◽  
Prnp Gene ◽  
Post Transcriptional Regulation

scholarly journals Nuclear-capture of endosomes depletes nuclear G-actin to promote SRF/MRTF activation and cancer cell invasion

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sergi Marco ◽  
Matthew Neilson ◽  
Madeleine Moore ◽  
Arantxa Perez-Garcia ◽  
Holly Hall ◽  
...  
Keyword(s):  
Nuclear Import ◽  
Tyrosine Kinases ◽  
Target Genes ◽  
Serum Response Factor ◽  
Actin Binding ◽  
Cell Scattering ◽  
Nuclear Localisation Sequence ◽  
Related Transcription Factor ◽  
Endosomal System ◽  
Serum Response

AbstractSignals are relayed from receptor tyrosine kinases (RTKs) at the cell surface to effector systems in the cytoplasm and nucleus, and coordination of this process is important for the execution of migratory phenotypes, such as cell scattering and invasion. The endosomal system influences how RTK signalling is coded, but the ways in which it transmits these signals to the nucleus to influence gene expression are not yet clear. Here we show that hepatocyte growth factor, an activator of MET (an RTK), promotes Rab17- and clathrin-dependent endocytosis of EphA2, another RTK, followed by centripetal transport of EphA2-positive endosomes. EphA2 then mediates physical capture of endosomes on the outer surface of the nucleus; a process involving interaction between the nuclear import machinery and a nuclear localisation sequence in EphA2’s cytodomain. Nuclear capture of EphA2 promotes RhoG-dependent phosphorylation of the actin-binding protein, cofilin to oppose nuclear import of G-actin. The resulting depletion of nuclear G-actin drives transcription of Myocardin-related transcription factor (MRTF)/serum-response factor (SRF)-target genes to implement cell scattering and the invasive behaviour of cancer cells.

Functional Involvement of Serum Response Factor in the Transcriptional Regulation of Caldesmon Gene

1998 ◽  
Vol 242 (2) ◽  
pp. 429-435 ◽  
Author(s):  
Takuya Momiyama ◽  
Ken'ichiro Hayashi ◽  
Hideto Obata ◽  
Yoshihiro Chimori ◽  
Toshirou Nishida ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Serum Response Factor ◽  
Response Factor ◽  
Functional Involvement ◽  
Serum Response
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