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.[5] It also has been shown to bind ANKRD23.[10]
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.[5] 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.[11]
^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 (November 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 (January 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 (October 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. S2CID14294292.
