Modulation of RIP1 ubiquitylation and distribution by MeBS to sensitize cancer cells to tumor necrosis factor α-induced apoptosis.
Overexpression of anti-apoptosis protein cIAP1 due to its genetic amplification is found in certain cancers such as esophageal squamous cell carcinoma, hepatocellular carcinoma, cervical cancer and lung cancer, and plays a significant role in resistance to cancer therapy. We previously reported that a class of small molecules represented by (-)-N-[(2S, 3R)-3-amino-2-hydroxy-4-phenyl-butyryl]-L-leucine methyl ester (MeBS) activates auto-ubiquitylation of cIAP1 for proteasomal degradation, and enhances apoptosis of various cancer cells. However, the molecular mechanism of how MeBS sensitizes cancer cells to apoptosis via downregulation of cIAP1 is not well understood. Here, we show that ubiquitylation and distribution of RIP1, a protein ubiquitylated by cIAP1, is modulated by MeBS. Upon tumor necrosis factor (TNF)α stimulation, ubiquitylated RIP1 associates with the TNF-receptor (TNFR) complex, whereas non-ubiquitylated RIP1 associates with caspase8. MeBS reduces the ubiquitylated RIP1 in the TNFR complex and increases non-ubiquitylated RIP1 bound to caspase8. Downregulation of RIP1 by siRNA reduces apoptosis induced by TNFα plus MeBS treatment. These results indicate an important role of RIP1 in apoptosis induced by combined treatment with TNFα and MeBS, suggesting that MeBS sensitizes cancer cells to apoptosis by modulating RIP1 ubiquitylation and distribution.
Kim
Seungseob
S
National Institute of Health Sciences, Tokyo Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan.
Ohoka
Nobumichi
N
Okuhira
Keiichiro
K
Sai
Kimie
K
Nishimaki-Mogami
Tomoko
T
Naito
Mikihiko
M
D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D053181:Caspase 8 / Q000378:metabolism; D045744:Cell Line, Tumor; D003513:Cycloheximide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000378:metabolism; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D034622:RNA Interference; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D020298:U937 Cells; D054875:Ubiquitination / Q000187:drug effects
D051034:Inhibitor of Apoptosis Proteins; C529718:MeBS compound; D011500:Protein Synthesis Inhibitors; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide; C506249:RIPK1 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; D053181:Caspase 8; D007930:Leucine
Curr Biol. 2000 Nov 2;10(21):1359-66
11084335
Cell. 2007 Nov 16;131(4):669-81
18022362
Cell Death Differ. 2007 Mar;14(3):400-10
17301840
Clin Cancer Res. 2000 May;6(5):1796-803
10815900
Cell. 2007 Nov 16;131(4):682-93
18022363
J Biol Chem. 2001 Feb 2;276(5):3238-46
11024045
EMBO J. 1997 Dec 1;16(23):6914-25
9384571
Nat Rev Mol Cell Biol. 2005 Apr;6(4):287-97
15803136
Mol Cell. 2008 Jun 20;30(6):689-700
18570872
Science. 2000 May 5;288(5467):874-7
10797013
J Biol Chem. 2006 Feb 10;281(6):3254-60
16339151
Nat Rev Mol Cell Biol. 2002 Jun;3(6):401-10
12042762
J Biol Chem. 1998 Apr 3;273(14):7787-90
9525868
Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8662-7
11447297
Cancer Res. 2001 Sep 15;61(18):6629-34
11559525
Blood. 1997 Mar 15;89(6):2060-6
9058728
Nat Cell Biol. 2004 Sep;6(9):849-60
15300255
FEBS Lett. 2004 May 21;566(1-3):151-6
15147886
Cell. 2008 May 16;133(4):693-703
18485876
J Biol Chem. 2008 Apr 4;283(14):8961-8
18230607
Mol Cell Biol. 2004 Oct;24(19):8418-27
15367663
Curr Biol. 2007 Mar 6;17(5):418-24
17306544
Cancer Res. 2002 Sep 1;62(17):4860-6
12208731
Cell. 1995 May 19;81(4):513-23
7538908
Nature. 1997 Jul 17;388(6639):300-4
9230442
EMBO Rep. 2006 Oct;7(10):988-94
17016456
Nature. 2001 Mar 1;410(6824):112-6
11242052
Cell. 2006 Jun 30;125(7):1253-67
16814713