CASP10
Каспаза-10 — это белок, который кодируется геном CASP10. Участвует в активации каскада каспаз, ответственных за апоптоз. Рекрутируется как к fas-, так и к TNFR-1 рецепторам в зависимости от FADD. Может участвовать в апоптотических путях гранзима В. Расщепляет и активирует каспазу-3, -4, -6, -7, -8 и -9. Гидролизует низкомолекулярные субстраты Tyr-Val-Ala-Asp-|-AMC и Asp-Glu-Val-Asp-|-AMC.
CASP10 gene encodes caspase-10, an initiator caspase that executes its role at the onset of apoptosis. Caspase-10 carries a large N-terminal prodomain with two DEDs (death effector domains), followed by the catalytic domain containing a large and small subunit separated by a linker region. Four different isoforms of caspase‐10 have been described: caspase-10a, 10b, 10c, 10d. Katherine Wachmann et al. uncovered that caspase-10 shares a similar activation mechanism and intrinsic substrate preference with its closely related paralog caspase-8, though with restricted tolerance in the P4 pocket. Upon a death stimulus, caspase-10 is expressed as a latent monomeric zymogen pro-caspase-10, which is recruited to a polymeric death-inducing signaling complex (DISC) containing the death receptors such as Fas or TRAIL, and adaptor protein FADD (Fas-associated death domain protein). These receptors are linked together through the interactions with FADD via homophilic interactions of DEDs. The DISC provides a platform for pro-caspase-10 dimerization with subsequent autocatalytic cleavage in the inter-subunit linker between their large and small chains, leading to proximity-induced activation. Once activated, caspase-10 directly activates the executioner caspases-3 and/or caspase-7, which leads to apoptosis or inflammation by cleaving specific sets of substrates. Although highly homologous to caspase-8, caspase-10 can not substitute for caspase‐8, as the defect in apoptosis induction observed in caspase‐8‐deficient cells could not be rescued by overexpression of caspase‐10. Mutations in caspase‐10 have been shown to lead to the human ALPS II (autoimmune lymphoproliferative syndrome type II) that is characterized by a defect in T‐cell and dendritic cell apoptosis
|
