The RIP‐like kinase, RIP3, induces apoptosis and NF‐κB nuclear translocation and localizes to mitochondria

Abstract

A RIP-like protein, RIP3, has recently been reported that contains an N-terminal kinase domain and a novel Cterminal domain that promotes apoptosis. These experiments further characterize RIP3-mediated apoptosis and NF-U UB activation. Northern blots indicate that rip3 mRNA displays a restricted pattern of expression including regions of the adult central nervous system. The rip3 gene was localized by fluorescent in situ hybridization to human chromosome 14q11.2, a region frequently altered in several types of neoplasia. RIP3-mediated apoptosis was inhibited by Bcl-2, Bcl-x L , dominant-negative FADD, as well as the general caspase inhibitor Z-VAD. Further dissection of caspase involvement in RIP3-induced apoptosis indicated inhibition by the more specific inhibitors Z-DEVD (caspase-3, -6, -7, -8, and -10) and Z-VDVAD (caspase-2). However, caspase-1, -6, -8 and -9 inhibitors had little or no effect on RIP3-mediated apoptosis. Mutational analysis of RIP3 revealed that the C-terminus of RIP3 contributed to its apoptotic activity. This region is similar, but distinct, to the death domain found in many pro-apoptotic receptors and adapter proteins, including FAS, FADD, TNFR1, and RIP. Furthermore, point mutations of RIP3 at amino acids conserved among death domains, abrogated its apoptotic activity. RIP3 was localized by immunofluorescence to the mitochondrion and may play a key role in the mitochondrial disruptions often associated with apoptosis.z 2000 Federation of European Biochemical Societies.

RIP3 overexpression sensitizes human breast cancer cells to parthenolide in vitro via intracellular ROS accumulation

“…This experiment also proved that RIP3 sensitized MCF-7 and MDA-MB-231 cells to PTL-induced apoptosis. Contrary to the report that RIP3 overexpression could induce apoptosis [19][20][21] , we did not observe any spontaneous apoptosis in our RIP3-MCF-7 or RIP3-MDA-MB-231 cells. This may be because previous work studied apoptosis as soon as 24 h after transient transfection of the RIP3 constructs, while we tested the cells after one-week antibiotic selection.…”

Receptor Interacting Protein 3 Suppresses Vascular Smooth Muscle Cell Growth by Inhibition of the Phosphoinositide 3-Kinase-Akt Axis

“…5A) and cell death ELISA (Fig. 5B), consistent with previous studies on other cell types (33)(34)(35)(36). Next, we envisioned that normalizing Akt activation by adenoviral gene transfer of the constitutively active PI3K mutant might protect cells from rRIP3-induced cell death.…”

“…Previous studies have demonstrated that RIP1 is obligated to tumor necrosis factor receptor-1-mediated NF-B activation and induces apoptosis and necrosis when overexpressed (30,31), whereas RIP1 deficiency prevents tumor necrosis factor-mediated activation of NF-B and enhances cell death (32). A large body of evidence suggests that RIP3 is also essentially involved in the tumor necrosis factor receptor-1 signaling pathway (33)(34)(35)(36) and that RIP3 binds to RIP1 and then exerts a potent apoptotic effect by interacting with some procaspases or by attenuating RIP1-and tumor necrosis factor receptor-1-mediated NF-B activation through phosphorylation of RIP1 (37). Moreover, in response to death receptor ligands, RIP3 can mediate both caspase-dependent and -independent apoptosis as well as NF-B activation (38).…”

RIPK3 contributes to TNFR1-mediated RIPK1 kinase-dependent apoptosis in conditions of cIAP1/2 depletion or TAK1 kinase inhibition

“…Our results on the kinase-independent role of RIPK3 in TNF-mediated apoptosis are in line with early work reporting apoptosis induction upon ectopic expression of KD RIPK3 mutants. 37,48 It was also previously reported that RIPK3 could, directly or indirectly, interact with the prodomain of caspase-8 upon ectopic expression. 37 It is therefore possible that the contribution of RIPK3 to TNF-mediated apoptosis involves another mechanism than ROS production.…”