TBC1 domain family member 21 (TBC1D21)

TBC1 domain family member 21 (TBC1D21) is a Rab GTPase-activating protein highly expressed in male germ cells where it plays an essential structural role in sperm development. It is involved in the assembly of the mitochondrial sheath and axoneme during spermiogenesis, interacting with key mitochondrial proteins (such as TOMM20), cytoskeletal proteins (such as actin and tropomyosin TPM3), and dynein DNAH7 to ensure proper sperm tail formation and function. TBC1D21 acts as a scaffold protein needed for the organization and stabilization of the sperm mitochondrial sheath, and its deficiency leads to male infertility due to disrupted sperm motility and abnormal mitochondrial and axonemal structures. It does not appear to be a therapeutic target or druggable receptor, but lower TBC1D21 transcript levels are associated with poor sperm morphology in human infertility[1][2][3][4].

Other names

MGCRABGAPMGC34741MgcRabGAPMale germ cell Rab GTPase-activating proteinmale germ cell-specific expressed containing a RabGAP domainTBC21