TPM4 is a member of the tropomyosin family. Tropomyosins exist in practically all eukaryotic cells （both muscle and nonmuscle）， where they bind actin filaments and function to modulate actin-myosin interaction and stabilize actin filament structure. TPM4 binds to actin filaments in muscle and nonmuscle cells and plays a central role， in connection with the troponin complex， in the calcium dependent regulation of vertebrate striated muscle contraction.
