RGD Reference Report - Mos activates myogenic differentiation by promoting heterodimerization of MyoD and E12 proteins. - Rat Genome Database

Send us a Message



Submit Data |  Help |  Video Tutorials |  News |  Publications |  Download |  REST API |  Citing RGD |  Contact   

Mos activates myogenic differentiation by promoting heterodimerization of MyoD and E12 proteins.

Authors: Lenormand, J L  Benayoun, B  Guillier, M  Vandromme, M  Leibovitch, M P  Leibovitch, S A 
Citation: Lenormand JL, etal., Mol Cell Biol. 1997 Feb;17(2):584-93. doi: 10.1128/MCB.17.2.584.
RGD ID: 596933305
Pubmed: PMID:9001211   (View Abstract at PubMed)
PMCID: PMC231783   (View Article at PubMed Central)
DOI: DOI:10.1128/MCB.17.2.584   (Journal Full-text)

The activities of myogenic basic helix-loop-helix (bHLH) factors are regulated by a number of different positive and negative signals. Extensive information has been published about the molecular mechanisms that interfere with the process of myogenic differentiation, but little is known about the positive signals. We previously showed that overexpression of rat Mos in C2C12 myoblasts increased the expression of myogenic markers whereas repression of Mos products by antisense RNAs inhibited myogenic differentiation. In the present work, our results show that the rat mos proto-oncogene activates transcriptional activity of MyoD protein. In transient transfection assays, Mos promotes transcriptional transactivation by MyoD of the muscle creatine kinase enhancer and/or a reporter gene linked to MyoD-DNA binding sites. Physical interaction between Mos and MyoD, but not with E12, is demonstrated in vivo by using the two-hybrid approach with C3H10T1/2 cells and in vitro by using the glutathione S-transferase (GST) pull-down assays. Unphosphorylated MyoD from myogenic cell lysates and/or bacterially expressed MyoD physically interacts with Mos. This interaction occurs via the helix 2 region of MyoD and a highly conserved region in Mos proteins with 40% similarity to the helix 2 domain of the E-protein class of bHLH factors. Phosphorylation of MyoD by activated GST-Mos protein inhibits the DNA-binding activity of MyoD homodimers and promotes MyoD-E12 heterodimer formation. These data support a novel function for Mos as a mediator (coregulator) of muscle-specific gene(s) expression.



Gene Ontology Annotations    Click to see Annotation Detail View

Molecular Function

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
MosRatMRF binding  IMP  RGD 
MosRatprotein serine kinase activity  IDA  RGD 

Objects Annotated

Genes (Rattus norvegicus)
Mos  (MOS proto-oncogene, serine/threonine kinase)


Additional Information