Table 1.
Binding partners for M2A, M2B and M2C that modify myosin function
| Binding Partner | Myosin 2 Isoform | Function of interaction | Selected reference |
|---|---|---|---|
| Actin | All | Generation of contractile force | Clark et al. (2007) |
| MLCK (myosin light chain kinase) | All | Activator - RLC (Ser19 and Thr18) phosphorylation - except for M2C-2 | Jana et al. (2009) |
| γ-PAK | M2A; M2B and M2C unknown | Activator - RLC (Ser19) phosphorylation | Chew et al. (1998) |
| Rho kinase (ROCK) | M2A > M2B; M2C unknown | Activator - RLC (direct) and MP (indirect) phosphorylation | Sandquist et al. (2006) |
| Citron kinase | Unknown specificity | Activator - through RLC phosphorylation | Yamashiro et al. (2003) |
| Zipper interacting protein (ZIP) kinase | Unknown specificity | Activator - through RLC phosphorylation | Ihara and MacDonald (2007) |
| MP (myosin phosphatase) | All | Inhibitor - dephosphorylation of phosphorylated RLC | Matsumura and Hartshorne (2008) |
| MRCK | Unknown specificity | Activator - RLC (direct) and MP (indirect) phosphorylation | Wilkinson et al. (2005) |
| S100A4 (Mts1) | M2A | Inhibitor - MHC (maps to 1909–1924); promotes filament disassembly | Li and Bresnick (2006) |
| PKCα/β | All | Modulator - RLC (Ser1, Ser2 and Thr9) - decreases affinity for MLCK | Komatsu and Ikebe (2007) |
| PKCβII | M2A and M2B | Activator - MHC (Ser1917 -M2A; multiple sites -M2B) phosphorylation | Ludowyke et al. (2006) |
| PKCγ | M2B | Activator - MHC (Ser1937 and Ser1952 + others) phosphorylation | Rosenberg and Ravid (2006) |
| aPKCζ | M2B | Inhibitor - MHC (Ser1937) phosphorylation | Even-Faitelson and Ravid (2006) |
| Casein kinase (CK) II | All | Activator - MHC (Ser1943) phosphorylation | Murakami et al. (1995) |
| CAMK II | M2A | Activator - MHC (Thr1940) phosphorylation | Buxton and Adelstein (2000) |
| TRPM7 | All | Inhibitor - through MHC phosphorylation at several sites | Clark et al. (2006) |
| cathepsin B | M2A | Proteolytic cleavage of M2A: enhances osteoclast fusion | McMichael et al. (2009) |
In each case, a single citation has been selected (often from among many) to facilitate entry to the relevant literature
CAMK calcium-calmodulin-dependent protein kinase, CK casein kinase, MHC myosin heavy chain, MLCK myosin light chain kinase, MP myosin phosphatase, MRCK myotonic dystrophy related-kinase cdc42 binding kinase, Mts1 metastasis-associated protein 1, PAK p21-activated kinase, PKC protein kinase C, RLC regulatory light chain, ROCK Rho-associated coiled-coil containing kinase, TRPM7 transient receptor potential melastatin 7, ZIP zipper interacting protein