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Protein MYH11 PDB 1br1.png
Aliases MYH11, AAT4, FAA4, SMHC, SMMHC, myosin, heavy chain 11, smooth muscle
External IDs MGI: 102643 HomoloGene: 128512 GeneCards: 4629
RNA expression pattern
PBB GE MYH11 201495 x at tn.png

PBB GE MYH11 201496 x at tn.png

PBB GE MYH11 201497 x at tn.png
More reference expression data
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)


Location (UCSC) Chr 16: 15.7 – 15.86 Mb Chr 16: 14.19 – 14.29 Mb
PubMed search [1] [2]
View/Edit Human View/Edit Mouse

Myosin-11 is a protein that in humans is encoded by the MYH11 gene.[3][4]


Myosin-11 is a smooth muscle myosin belonging to the myosin heavy chain family. Myosin-11 is a subunit of a hexameric protein that consists of two heavy chain subunits and two pairs of non-identical light chain subunits.

It is a major contractile protein, converting chemical energy into mechanical energy through the hydrolysis of ATP.

Alternative splicing generates isoforms that are differentially expressed, with ratios changing during muscle cell maturation.[4]

Clinical significance[edit]

Thoracic aortic aneurysms leading to acute aortic dissections (TAAD) can be inherited in isolation or in association with genetic syndromes, such as Marfan syndrome and Loeys-Dietz syndrome. When TAAD occurs in the absence of syndromic features, it is inherited in an autosomal dominant manner with decreased penetrance and variable expression, the disease is referred to as familial TAAD. Familial TAAD exhibits significant clinical and genetic heterogeneity. Mutations in MYH11 have been described in individuals with TAAD with patent ductus arteriosus (PDA). Of individuals with TAAD, approximately 4% have mutations in TGFBR2, and approximately 1-2% have mutations in either TGFBR1 or MYH11. In addition, FBN1 mutations have also been reported in individuals with TAAD. Mutations within the SMAD3 gene have recently been reported in patients with a syndromic form of aortic aneurysms and dissections with early onset osteoarthritis. SMAD3 mutations are thought to account for approximately 2% of familial TAAD. Additionally, mutations in the ACTA2 gene are thought to account for approximately 10-14% of familial TAAD.[5]

Acute myeloid leukemia[edit]

The gene encoding a human ortholog of rat NUDE1 is transcribed from the reverse strand of this gene, and its 3' end overlaps with that of the latter. The pericentric inversion of chromosome 16 [inv(16)(p13q22)] produces a chimeric transcript that encodes a protein consisting of the first 165 residues from the N-terminus of core-binding factor beta in a fusion with the C-terminal portion of the smooth muscle myosin heavy chain. This chromosomal rearrangement is associated with acute myeloid leukemia of the M4Eo subtype.

Intestinal cancer[edit]

MYH11 mutations appear to contribute to human intestinal cancer.[6]


  1. ^ "Human PubMed Reference:". 
  2. ^ "Mouse PubMed Reference:". 
  3. ^ Matsuoka R, Yoshida MC, Furutani Y, Imamura S, Kanda N, Yanagisawa M, Masaki T, Takao A (Jun 1993). "Human smooth muscle myosin heavy chain gene mapped to chromosomal region 16q12". Am J Med Genet. 46 (1): 61–7. doi:10.1002/ajmg.1320460110. PMID 7684189. 
  4. ^ a b "Entrez Gene: MYH11 myosin, heavy chain 11, smooth muscle". 
  5. ^ Boston University Center for Human Genetics - Aortic Aneurysms
  6. ^ Alhopuro P, Phichith D, Tuupanen S, Sammalkorpi H, Nybondas M, Saharinen J, Robinson JP, Yang Z, Chen LQ, Orntoft T, Mecklin JP, Järvinen H, Eng C, Moeslein G, Shibata D, Houlston RS, Lucassen A, Tomlinson IP, Launonen V, Ristimäki A, Arango D, Karhu A, Sweeney HL, Aaltonen LA (April 2008). "Unregulated smooth-muscle myosin in human intestinal neoplasia". Proc. Natl. Acad. Sci. U.S.A. 105 (14): 5513–8. doi:10.1073/pnas.0801213105. PMC 2291082free to read. PMID 18391202. 

External links[edit]

Further reading[edit]