MYL3

Myosin, light chain 3, alkali; ventricular, skeletal, slow
Identifiers
Symbols	MYL3 ; CMH8; MLC1SB; MLC1V; VLC1
External IDs	OMIM: 160790 MGI: 97268 HomoloGene: 20099 GeneCards: MYL3 Gene
Gene ontology Molecular function • motor activity • actin monomer binding • calcium ion binding • structural constituent of muscle • myosin II heavy chain binding Cellular component • cytosol • muscle myosin complex • sarcomere • A band • I band Biological process • regulation of the force of heart contraction • regulation of striated muscle contraction • skeletal muscle tissue development • metabolic process • muscle filament sliding • positive regulation of ATPase activity • ventricular cardiac muscle tissue morphogenesis • cardiac muscle contraction Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	4634	17897
Ensembl	ENSG00000160808	ENSMUSG00000059741
UniProt	P08590	P09542
RefSeq (mRNA)	NM_000258	NM_010859
RefSeq (protein)	NP_000249	NP_034989
Location (UCSC)	Chr 3: 46.86 – 46.88 Mb	Chr 9: 110.74 – 110.77 Mb
PubMed search

Myosin essential light chain (ELC), ventricular/cardiac isoform is a protein that in humans is encoded by the MYL3 gene.^[1][2][3] This cardiac ventricular/slow skeletal ELC isoform is distinct from that expressed in fast skeletal muscle (MYL1) and cardiac atrial muscle (MYL4). Ventricular ELC is part of the myosin molecule and is important in modulating cardiac muscle contraction.

Structure

Cardiac, ventricular ELC is 21.9 kDa and composed of 195 amino acids (See human MYL3 sequences features here). Cardiac ELC and the second light chain, regulatory light chain (RLC, MYL2), are non-covalently bound to IQXXXRGXXXR motifs in the 9 nm S1-S2 lever arm of the myosin head,^[4] both alpha (MYH6) and beta (MYH7) isoforms. Both light chains are members of the EF-hand superfamily of proteins, which possess helix-loop-helix motifs in two globular domains connected by an alpha-helical linker. Though EF hand motifs are specialized to bind divalent ions such as calcium, cardiac ELC does not bind calcium at physiological levels.^[5] The N-terminal region of cardiac ELC is functionlly unique in that it is positively charged, being rich in Lysine residues (amino acids 4-14), with subsequent unique structure governed by Proline-Alanine repeats (amino acids 15-36).

Function

Studies have provided evidence for ELC as modulator of myosin crossbrige kinetics. Treating cardiac myofibrils with the Lysine-rich N-terminal peptide (amino acids 5-14) evoked a supramaximal increase in cardiac myofibrillar MgATPase activity at submaximal calcium concentrations,^[6] and further studies demonstrated that this region of ELC modulates the affinity of myosin for actin.^[7]

Clinical significance

Mutations in MYL3 have been identified as a cause of familial hypertrophic cardiomyopathy, and associated with a mid-left ventricular chamber type hypertrophy.^[8] Five mutations in MYL3 have been identified to date: M149V, R154H, E56G, A57G and E143K.^{[9][10][11][12]} All of these cluster around two of the four EF-hand domains, suggesting that proper conformation in these regions is necessary for normal cardiac function.^[8]

References

1. Shi Q, Li RK, Mickle DA, Jackowski G (Nov 1992). "Analysis of the upstream regulatory region of human ventricular myosin light chain 1 gene". Journal of Molecular and Cellular Cardiology 24 (11): 1221–9. doi:10.1016/0022-2828(92)93089-3. PMID 1479618.
2. Cohen-Haguenauer O, Barton PJ, Van Cong N, Cohen A, Masset M, Buckingham M, Frézal J (Feb 1989). "Chromosomal assignment of two myosin alkali light-chain genes encoding the ventricular/slow skeletal muscle isoform and the atrial/fetal muscle isoform (MYL3, MYL4)". Human Genetics 81 (3): 278–82. doi:10.1007/bf00279004. PMID 2784124.
3. "Entrez Gene: MYL3 myosin, light chain 3, alkali; ventricular, skeletal, slow".
4. Rayment I, Rypniewski WR, Schmidt-Bäse K, Smith R, Tomchick DR, Benning MM, Winkelmann DA, Wesenberg G, Holden HM (1993). "Three-dimensional structure of myosin subfragment-1: a molecular motor". Science 261 (5117): 50–8. doi:10.1126/science.8316857. PMID 8316857.
5. Collins JH (1991). "Myosin light chains and troponin C: structural and evolutionary relationships revealed by amino acid sequence comparisons". J. Muscle Res. Cell. Motil. 12 (1): 3–25. doi:10.1007/bf01781170. PMID 2050809.
6. Rarick HM, Opgenorth TJ, von Geldern TW, Wu-Wong JR, Solaro RJ (1996). "An essential myosin light chain peptide induces supramaximal stimulation of cardiac myofibrillar ATPase activity". J. Biol. Chem. 271 (43): 27039–43. PMID 8900193.
7. Stepkowski D, Efimova N, Paczyņska A, Moczarska A, Nieznańska H, Kakol I (1997). "The possible role of myosin A1 light chain in the weakening of actin-myosin interaction". Biochim. Biophys. Acta 1340 (1): 105–14. doi:10.1016/s0167-4838(97)00031-9. PMID 9217020.
8. Harris, S. P.; Lyons, R. G.; Bezold, K. L. (2011). "In the thick of it: HCM-causing mutations in myosin binding proteins of the thick filament". Circulation Research 108 (6): 751–64. doi:10.1161/CIRCRESAHA.110.231670. PMC 3076008. PMID 21415409.
9. Poetter, K; Jiang, H; Hassanzadeh, S; Master, S. R.; Chang, A; Dalakas, M. C.; Rayment, I; Sellers, J. R.; Fananapazir, L; Epstein, N. D. (1996). "Mutations in either the essential or regulatory light chains of myosin are associated with a rare myopathy in human heart and skeletal muscle". Nature Genetics 13 (1): 63–9. doi:10.1038/ng0596-63. PMID 8673105.
10. Richard, P; Charron, P; Carrier, L; Ledeuil, C; Cheav, T; Pichereau, C; Benaiche, A; Isnard, R; Dubourg, O; Burban, M; Gueffet, J. P.; Millaire, A; Desnos, M; Schwartz, K; Hainque, B; Komajda, M; Eurogene Heart Failure, Project (2003). "Hypertrophic cardiomyopathy: Distribution of disease genes, spectrum of mutations, and implications for a molecular diagnosis strategy". Circulation 107 (17): 2227–32. doi:10.1161/01.CIR.0000066323.15244.54. PMID 12707239.
11. Lee, W; Hwang, T. H.; Kimura, A; Park, S. W.; Satoh, M; Nishi, H; Harada, H; Toyama, J; Park, J. E. (2001). "Different expressivity of a ventricular essential myosin light chain gene Ala57Gly mutation in familial hypertrophic cardiomyopathy". American Heart Journal 141 (2): 184–9. doi:10.1067/mhj.2001.112487. PMID 11174330.
12. Olson, T. M.; Karst, M. L.; Whitby, F. G.; Driscoll, D. J. (2002). "Myosin light chain mutation causes autosomal recessive cardiomyopathy with mid-cavitary hypertrophy and restrictive physiology". Circulation 105 (20): 2337–40. doi:10.1161/01.cir.0000018444.47798.94. PMID 12021217.

Further reading

• Schaub MC, Hefti MA, Zuellig RA, Morano I (Feb 1998). "Modulation of contractility in human cardiac hypertrophy by myosin essential light chain isoforms". Cardiovascular Research 37 (2): 381–404. doi:10.1016/S0008-6363(97)00258-7. PMID 9614495.
• Stragier P, Kunkel B, Kroos L, Losick R (Jan 1989). "Chromosomal rearrangement generating a composite gene for a developmental transcription factor". Science 243 (4890): 507–12. doi:10.1126/science.2536191. PMID 2536191.
• Fodor WL, Darras B, Seharaseyon J, Falkenthal S, Francke U, Vanin EF (Feb 1989). "Human ventricular/slow twitch myosin alkali light chain gene characterization, sequence, and chromosomal location". The Journal of Biological Chemistry 264 (4): 2143–9. PMID 2789520.
• Hoffmann E, Shi QW, Floroff M, Mickle DA, Wu TW, Olley PM, Jackowski G (Mar 1988). "Molecular cloning and complete nucleotide sequence of a human ventricular myosin light chain 1". Nucleic Acids Research 16 (5): 2353. doi:10.1093/nar/16.5.2353. PMC 338240. PMID 3357795.
• Kurabayashi M, Komuro I, Tsuchimochi H, Takaku F, Yazaki Y (Sep 1988). "Molecular cloning and characterization of human atrial and ventricular myosin alkali light chain cDNA clones". The Journal of Biological Chemistry 263 (27): 13930–6. PMID 3417683.
• Henry GD, Trayer IP, Brewer S, Levine BA (Apr 1985). "The widespread distribution of alpha-N-trimethylalanine as the N-terminal amino acid of light chains from vertebrate striated muscle myosins". European Journal of Biochemistry / FEBS 148 (1): 75–82. doi:10.1111/j.1432-1033.1985.tb08809.x. PMID 3979397.
• Kovalyov LI, Shishkin SS, Efimochkin AS, Kovalyova MA, Ershova ES, Egorov TA, Musalyamov AK (Jul 1995). "The major protein expression profile and two-dimensional protein database of human heart". Electrophoresis 16 (7): 1160–9. doi:10.1002/elps.11501601192. PMID 7498159. Check date values in: |year= / |date= mismatch (help)
• Poetter K, Jiang H, Hassanzadeh S, Master SR, Chang A, Dalakas MC, Rayment I, Sellers JR, Fananapazir L, Epstein ND (May 1996). "Mutations in either the essential or regulatory light chains of myosin are associated with a rare myopathy in human heart and skeletal muscle". Nature Genetics 13 (1): 63–9. doi:10.1038/ng0596-63. PMID 8673105.
• Takeuchi K, Senba S, Furukawa K, Eto M, Morita F (Feb 1999). "Localization of 17-kDa myosin light chain isoforms in cultured aortic smooth muscle cells". Journal of Biochemistry 125 (2): 334–42. doi:10.1093/oxfordjournals.jbchem.a022291. PMID 9990131.
• Andersen PS, Havndrup O, Bundgaard H, Moolman-Smook JC, Larsen LA, Mogensen J, Brink PA, Børglum AD, Corfield VA, Kjeldsen K, Vuust J, Christiansen M (Dec 2001). "Myosin light chain mutations in familial hypertrophic cardiomyopathy: phenotypic presentation and frequency in Danish and South African populations". Journal of Medical Genetics 38 (12): E43. doi:10.1136/jmg.38.12.e43. PMC 1734772. PMID 11748309. Check date values in: |year= / |date= mismatch (help)
• Olson TM, Karst ML, Whitby FG, Driscoll DJ (May 2002). "Myosin light chain mutation causes autosomal recessive cardiomyopathy with mid-cavitary hypertrophy and restrictive physiology". Circulation 105 (20): 2337–40. doi:10.1161/01.CIR.0000018444.47798.94. PMID 12021217.
• Moretti A, Weig HJ, Ott T, Seyfarth M, Holthoff HP, Grewe D, Gillitzer A, Bott-Flügel L, Schömig A, Ungerer M, Laugwitz KL (Sep 2002). "Essential myosin light chain as a target for caspase-3 in failing myocardium". Proceedings of the National Academy of Sciences of the United States of America 99 (18): 11860–5. doi:10.1073/pnas.182373099. PMC 129359. PMID 12186978.
• Richard P, Charron P, Carrier L, Ledeuil C, Cheav T, Pichereau C, Benaiche A, Isnard R, Dubourg O, Burban M, Gueffet JP, Millaire A, Desnos M, Schwartz K, Hainque B, Komajda M (May 2003). "Hypertrophic cardiomyopathy: distribution of disease genes, spectrum of mutations, and implications for a molecular diagnosis strategy". Circulation 107 (17): 2227–32. doi:10.1161/01.CIR.0000066323.15244.54. PMID 12707239.
• Xie B, Huang R, Huang L, Zhou G, Gong Z (Oct 2003). "The functional domains of human ventricular myosin light chain 1". Biophysical Chemistry 106 (1): 57–66. doi:10.1016/S0301-4622(03)00172-8. PMID 14516912. Check date values in: |year= / |date= mismatch (help)
• Suzuki Y, Yamashita R, Shirota M, Sakakibara Y, Chiba J, Mizushima-Sugano J, Nakai K, Sugano S (Sep 2004). "Sequence comparison of human and mouse genes reveals a homologous block structure in the promoter regions". Genome Research 14 (9): 1711–8. doi:10.1101/gr.2435604. PMC 515316. PMID 15342556.

External links

• Mass spectrometry characterization of MYL3 at COPaKB
• GeneReviews/NIH/NCBI/UW entry on Familial Hypertrophic Cardiomyopathy Overview