Myosin light-chain kinase Information & Myosin light-chain kinase Links at HealthHaven.com

myosin light chain kinase 3, cardiac
Identifiers
Symbol	MYLK3
Entrez	91807
HUGO	29826
OMIM	612147
RefSeq	NM_182493
UniProt	Q32MK0
Other data
Locus	Chr. 16 q11.2

myosin light chain kinase 2, skeletal muscle
Identifiers
Symbol	MYLK2
Entrez	85366
HUGO	16243
OMIM	606566
RefSeq	NM_033118
UniProt	Q9H1R3
Other data
Locus	Chr. 20 q13.31

myosin, light polypeptide kinase, smooth muscle
Identifiers
Symbol	MYLK
Entrez	4638
HUGO	7590
OMIM	600922
RefSeq	NM_053025
UniProt	Q15746
Other data
EC number	2.7.11.18
Locus	Chr. 3 qcen-q21

myosin light chain kinase family, member 4
Identifiers
Symbol	MYLK4
Entrez	340156
HUGO	27972
RefSeq	NM_001012418
UniProt	Q86YV6
Other data
Locus	Chr. 6 p25.2

Myosin-light-chain kinase also known as MYLK or MLCK is a serine/threonine-specific protein kinase that phosphorylates the regulatory light chain of myosin II.^[1]

[edit] Isoforms

Four different MLCK isoforms exist:^[2]

MYLK – smooth muscle
MYLK2 – skeletal
MYLK3 – cardiac
MYLK4 – novel

[edit] Function

These enzymes are important in the mechanism of contraction in muscle. Once there is an influx of calcium cations (Ca⁺⁺) into the muscle, either from the sarcoplasmic reticulum or, more importantly, from the extracellular space, contraction of smooth muscle fibers may begin. First, the calcium will bind to calmodulin. This binding will activate MLCK, which will go on to phosphorylate the myosin light chain at serine residue 19. This will enable the myosin crossbridge to bind to the actin filament and allow contraction to begin (through the crossbridge cycle). Since smooth muscle does not contain a troponin complex like striated muscle does, this mechanism is the main pathway for regulating smooth muscle contraction.

[edit] See also

protein kinase A

[edit] References

^ Gao Y, Ye LH, Kishi H, Okagaki T, Samizo K, Nakamura A, Kohama K (June 2001). "Myosin light chain kinase as a multifunctional regulatory protein of smooth muscle contraction". IUBMB Life 51 (6): 337–44. PMID 11758800.
^ Manning G, Whyte DB, Martinez R, Hunter T, Sudarsanam S (December 2002). "The protein kinase complement of the human genome". Science (journal) 298 (5600): 1912–34. doi:10.1126/science.1075762. PMID 12471243.

[edit] Further reading

Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. doi:10.1073/pnas.242603899. PMID 12477932.
Gerhard DS, Wagner L, Feingold EA, et al. (2004). "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).". Genome Res. 14 (10B): 2121–7. doi:10.1101/gr.2596504. PMID 15489334.
Clayburgh DR, Rosen S, Witkowski ED, et al. (2005). "A differentiation-dependent splice variant of myosin light chain kinase, MLCK1, regulates epithelial tight junction permeability.". J. Biol. Chem. 279 (53): 55506–13. doi:10.1074/jbc.M408822200. PMID 15507455.
Wang F, Graham WV, Wang Y, et al. (2005). "Interferon-gamma and tumor necrosis factor-alpha synergize to induce intestinal epithelial barrier dysfunction by up-regulating myosin light chain kinase expression.". Am. J. Pathol. 166 (2): 409–19. PMID 15681825.
Russo JM, Florian P, Shen L, et al. (2005). "Distinct temporal-spatial roles for rho kinase and myosin light chain kinase in epithelial purse-string wound closure.". Gastroenterology 128 (4): 987–1001. PMID 15825080.
Shimizu S, Yoshida T, Wakamori M, et al. (2006). "Ca2+-calmodulin-dependent myosin light chain kinase is essential for activation of TRPC5 channels expressed in HEK293 cells.". J. Physiol. (Lond.) 570 (Pt 2): 219–35. doi:10.1113/jphysiol.2005.097998. PMID 16284075.
Kim MT, Kim BJ, Lee JH, et al. (2006). "Involvement of calmodulin and myosin light chain kinase in activation of mTRPC5 expressed in HEK cells.". Am. J. Physiol., Cell Physiol. 290 (4): C1031–40. doi:10.1152/ajpcell.00602.2004. PMID 16306123.
Kimura K, Wakamatsu A, Suzuki Y, et al. (2006). "Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes.". Genome Res. 16 (1): 55–65. doi:10.1101/gr.4039406. PMID 16344560.
Connell LE, Helfman DM (2007). "Myosin light chain kinase plays a role in the regulation of epithelial cell survival.". J. Cell. Sci. 119 (Pt 11): 2269–81. doi:10.1242/jcs.02926. PMID 16723733.
Seguchi O, Takashima S, Yamazaki S, et al. (2007). "A cardiac myosin light chain kinase regulates sarcomere assembly in the vertebrate heart.". J. Clin. Invest. 117 (10): 2812–24. doi:10.1172/JCI30804. PMID 17885681.

[edit] External links

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

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[pmid11758800-0] Gao Y, Ye LH, Kishi H, Okagaki T, Samizo K, Nakamura A, Kohama K (June 2001). "Myosin light chain kinase as a multifunctional regulatory protein of smooth muscle contraction". IUBMB Life 51 (6): 337–44. PMID 11758800.

[pmid12471243-1] Manning G, Whyte DB, Martinez R, Hunter T, Sudarsanam S (December 2002). "The protein kinase complement of the human genome". Science (journal) 298 (5600): 1912–34. doi:10.1126/science.1075762. PMID 12471243.

[1]

[2]