Myopalladin is a 145.2 kDa protein composed of 1320 amino acids.[8][9] Myopalladin has five Ig-like repeats within the protein, and a proline-rich domain. Myopalladin binds the Src homology domain of nebulette and nebulin and tethers it to alpha-actinin via its C-terminal domain binding to the EF hand domains of alpha-actinin. The N-terminal region of myopalladin binds to the nuclear protein CARP, known to regulate gene expression in muscle.[10] It also has been shown to bind ANKRD23.[11]
Function
Myopalladin has dual subcellular localization, residing in both the nucleus and sarcomere/I-bands in muscle. Accordingly, myopalladin has functions in both sarcomere assembly and in control of gene expression.[10] Specifics of these functions were gleaned from studies involving MYPN mutants associated with various cardiomyopathies. The Q529X myopalladin mutant demonstrated incompetence in recruiting key binding partners such as desmin, alpha-actinin and CARP to the Z-disc during myofibrilogenesis. In contrast, the Y20C mutant resulted in decreased expression of binding partners.[12]
^Ma K, Wang K (Dec 2002). "Interaction of nebulin SH3 domain with titin PEVK and myopalladin: implications for the signaling and assembly role of titin and nebulin". FEBS Letters. 532 (3): 273–8. doi:10.1016/S0014-5793(02)03655-4. PMID12482578.
^Chung, Joon-Sub. "Protein Information - Myopalladin". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB). NHLBI Proteomics Center at UCLA. Retrieved 2015-04-29.
^Miller MK, Bang ML, Witt CC, Labeit D, Trombitas C, Watanabe K, Granzier H, McElhinny AS, Gregorio CC, Labeit S (Nov 2003). "The muscle ankyrin repeat proteins: CARP, ankrd2/Arpp and DARP as a family of titin filament-based stress response molecules". Journal of Molecular Biology. 333 (5): 951–64. doi:10.1016/j.jmb.2003.09.012. PMID14583192.
^ abPurevjav E, Arimura T, Augustin S, Huby AC, Takagi K, Nunoda S, Kearney DL, Taylor MD, Terasaki F, Bos JM, Ommen SR, Shibata H, Takahashi M, Itoh-Satoh M, McKenna WJ, Murphy RT, Labeit S, Yamanaka Y, Machida N, Park JE, Alexander PM, Weintraub RG, Kitaura Y, Ackerman MJ, Kimura A, Towbin JA (May 2012). "Molecular basis for clinical heterogeneity in inherited cardiomyopathies due to myopalladin mutations". Human Molecular Genetics. 21 (9): 2039–53. doi:10.1093/hmg/dds022. PMID22286171.
^Duboscq-Bidot L, Xu P, Charron P, Neyroud N, Dilanian G, Millaire A, Bors V, Komajda M, Villard E (Jan 2008). "Mutations in the Z-band protein myopalladin gene and idiopathic dilated cardiomyopathy". Cardiovascular Research. 77 (1): 118–25. doi:10.1093/cvr/cvm015. PMID18006477.
Miller MK, Bang ML, Witt CC, Labeit D, Trombitas C, Watanabe K, Granzier H, McElhinny AS, Gregorio CC, Labeit S (Nov 2003). "The muscle ankyrin repeat proteins: CARP, ankrd2/Arpp and DARP as a family of titin filament-based stress response molecules". Journal of Molecular Biology. 333 (5): 951–64. doi:10.1016/j.jmb.2003.09.012. PMID14583192.
Mehrle A, Rosenfelder H, Schupp I, del Val C, Arlt D, Hahne F, Bechtel S, Simpson J, Hofmann O, Hide W, Glatting KH, Huber W, Pepperkok R, Poustka A, Wiemann S (Jan 2006). "The LIFEdb database in 2006". Nucleic Acids Research. 34 (Database issue): D415–8. doi:10.1093/nar/gkj139. PMC1347501. PMID16381901.
Beausoleil SA, Villén J, Gerber SA, Rush J, Gygi SP (Oct 2006). "A probability-based approach for high-throughput protein phosphorylation analysis and site localization". Nature Biotechnology. 24 (10): 1285–92. doi:10.1038/nbt1240. PMID16964243.