Key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The size and extensibility of the cross-links are the main determinants of sarcomere extensibility properties of muscle. In non-muscle cells, seems to play a role in chromosome condensation and chromosome segregation during mitosis. Might link the lamina network to chromatin or nuclear actin, or both during interphase.
Interacts with MYOM1, MYOM2, tropomyosin and myosin. Interacts with actin, primarily via the PEVK domains and with MYPN (By similarity). Interacts with FHL2, NEB, CRYAB, LMNA/lamin-A and LMNB/lamin-B. Interacts with TCAP/telethonin and/or ANK1 isoform Mu17/ank1.5, via the first two N-terminal immunoglobulin domains. Interacts with TRIM63 and TRIM55, through several domains including immunoglobulin domains 141 and 142. Interacts with ANKRD1, ANKRD2 and ANKRD23, via the region between immunoglobulin domains 77 and 78 and interacts with CAPN3, via immunoglobulin domain 79. Interacts with NBR1 through the protein kinase domain. Interacts with CALM/calmodulin. Isoform 8 interacts with OBSCN isoform 3.