Myosin regulatory light chain 12A (MYL12A)

The protein contains 171 amino acids for an estimated molecular weight of 19794 Da.

 

Myosin regulatory subunit that plays an important role in regulation of both smooth muscle and nonmuscle cell contractile activity via its phosphorylation. Implicated in cytokinesis, receptor capping, and cell locomotion (By similarity). (updated: April 1, 2015)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
  3. Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
  4. Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

Interpro domains
Total structural coverage: 100%
Model score: 51

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The reference OMIM entry for this protein is 609211

Myosin, light chain 12b, regulatory; myl12b
Myosin regulatory light chain 2; mrlc2

DESCRIPTION

The activity of nonmuscle myosin II (see MYH9; 160775) is regulated by phosphorylation of a regulatory light chain, such as MRLC2. This phosphorylation results in higher MgATPase activity and the assembly of myosin II filaments (Iwasaki et al., 2001).

CLONING

Grant et al. (1990) cloned MRLC2 from a placenta cDNA library. The deduced protein contains 171 amino acids. Using primers designed from chicken Mrlc, Iwasaki et al. (2001) amplified MRLC2 from a HeLa cell cDNA library. The deduced 172-amino acid protein contains thr18 and ser19, which are conserved phosphorylation sites in myosin regulatory light chains.

GENE FUNCTION

Diphosphorylation of MRLCs on thr18 and ser19 results in higher MgATPase activity and myosin filament formation than monophosphorylation at ser19 in vitro. By site-directed mutagenesis, Iwasaki et al. (2001) created MRLC2 mutants that mimicked diphosphorylated, monophosphorylated, and unphosphorylated forms of MRLC2. Overexpression of the diphosphorylated form, and to a lesser degree the monophosphorylated form, caused the formation of a large number of actin filament bundles in transfected HeLa cells. Overexpression of the unphosphorylated form caused a decrease in the number of actin filament bundles. Immunolocalization of the mutant proteins in dividing cells revealed colocalization of the 2 phosphorylated forms with actin filaments in the peripheral region and with the contractile ring, while the unphosphorylated form localized diffusely throughout the cytoplasm. Iwasaki et al. (2001) concluded that phosphorylation of MRLC2 is required for organization of stress fibers in interphase cells and the contractile ring in dividing cells. They suggested that diphosphorylated MRLC may be more effective in organizing actin filaments than monophosphorylated MRLC.

MAPPING

The International Radiation Hybrid Mapping Consortium mapped the MYL12B gene to chromosome 18 (TMAP SHGC-12353). ... More on the omim web site

Subscribe to this protein entry history

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated

June 20, 2017: Protein entry updated
Automatic update: comparative model was added.

March 25, 2017: Additional information
No protein expression data in P. Mayeux work for MYL12A

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 609211 was added.