Note | The start of translation is in exon 2 (prior to the alternative splice donors). Alternative splicing causes a frame shift resulting in transcripts encoding proteins with different C-termini and separate stop codons in exon 4. The stop codon for ARC is 43 bp upstream of that of NOP30. |
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| Alternatively spliced transcripts of NOL3 lead to two different proteins, ARC (blue) and NOP30 (red). These proteins each contain an N-terminal CARD (first 95 amino acids identical), but have different C-termini. The C-terminus of ARC is rich in prolines and glutamic acids, whereas the C-terminus of NOP30 is rich in serines and arginines. |
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Description | Human ARC protein contains 208 amino acids with Mr 22,629 Da. The protein usually runs at a slower mobility on SDS-PAGE most likely due to the enrichment of proline residues in the C-terminal domain. NOP30 contains 219 amino acids with Mr 24,327 Da. |
Expression | Under normal conditions, ARC mRNA and protein is present predominantly in cardiac myocytes, skeletal myocytes, and neurons (Koseki et al., 1998; Abmayr et al., 2004; Geertman et al., 1996; Engidawork et al., 2001). ARC protein is also markedly increased in primary human epithelial cancers of the breast, colon, ovary, and cervix (Mercier et al., 2005; Mercier et al., 2008). NOP30 transcripts are present in some human cell types but have not been detected in mouse cells. Endogenous NOP30 protein has not been demonstrated in cells of any species. |
Localisation | Endogenous ARC protein is present in the cytoplasm and nucleoplasm (Mercier et al., 2005). As above, the localization of endogenous NOP30 protein has not been investigated. Exogenously expressed NOP30 protein localizes in the nucleolus and nucleoplasm. |
Function | The function of endogenous NOP30 is not known. Exogenous NOP30 interacts with SFRS9/SRp30C and NPM1 and may influence splicing (Stoss et al., 1999). ARC is an endogenous inhibitor of apoptosis that is unique in its ability to antagonize both the extrinsic (death receptor) and the intrinsic (mitochondria/ER) death pathways (Nam et al., 2004; Gustafsson et al., 2004; Koseki et al., 1998). ARC inhibits the extrinsic pathway by interfering with DISC (Death Inducing Signaling Complex) formation. This is accomplished by the direct interaction of the ARC CARD with the death domains (DD) of Fas and FADD, and with the death effector domain (DED) of procaspase-8. These death-fold interactions are novel in that they are heterotypic in contrast to the usual homotypic death-fold interactions. ARC inhibits the intrinsic pathway through at least two mechanisms. First, the direct interaction between the ARC CARD and the C-terminus of Bax inhibits death stimulus-induced Bax conformational activation and translocation to the mitochondria. Second, direct interaction between the ARC C-terminal domain with the p53 tetramerization domain inhibits p53 tetramerization (Foo et al., PNAS, 2007). This, in turn, disables p53 transcriptional function and exposes a p53 nuclear export signal that relocates p53 to the cytoplasm. Nothing is known about the regulation of NOP30. The regulation of ARC is complex. ARC protein abundance decreases rapidly and dramatically in response to hypoxia and oxidative stress (e.g. ischemia-reperfusion) (Ekhterae et al., 1999; Neuss et al., 2001; Nam et al., 2007). These decreases result from increased degradation of ARC protein via the ubiquitin-proteasomal pathway (Nam et al., 2007). The E3 ligase MDM2 may play a role in ARC degradation in this scenario (Foo et al., JBC, 2007), but this role is probably indirect (L. Wu and R. Kitsis, unpublished data). Decreases in ARC protein abundance in response to hypoxia appear to be regulated by p53 repression of nol3 transcription (Li et al., 2008). Apart from ARC protein abundance, the activity of ARC is also regulated post-translationally: dephosphorylation of threonine 149 decreases the anti-apoptotic activity of ARC (Tan et al., 2008). |
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| Regulation of the extrinsic (death receptor) and intrinsic (mitochondria/ER) apoptosis pathways by ARC. Not shown are ARC interactions with and regulation of p53. |
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Homology | ARC is highly conserved among mammals. There is approximately 85% identity both at the amino acid and the nucleotide level among human, rat, mouse, dog, and bovine ARC. Interestingly, an ARC homolog has yet to be identified in Danio rerio, Drosophila melanogaster, or Caenorhabditis elegans. |
Characterization of ARC, apoptosis repressor interacting with CARD, in normal and dystrophin-deficient skeletal muscle. |
Abmayr S, Crawford RW, Chamberlain JS. |
Hum Mol Genet. 2004 Jan 15;13(2):213-21. Epub 2003 Nov 25. |
PMID 14645204 |
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Inhibition of endoplasmic reticulum stress-induced apoptosis of melanoma cells by the ARC protein. |
Chen LH, Jiang CC, Watts R, Thorne RF, Kiejda KA, Zhang XD, Hersey P. |
Cancer Res. 2008 Feb 1;68(3):834-42. |
PMID 18245485 |
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Apoptosis repressor with caspase recruitment domain is required for cardioprotection in response to biomechanical and ischemic stress. |
Donath S, Li P, Willenbockel C, Al-Saadi N, Gross V, Willnow T, Bader M, Martin U, Bauersachs J, Wollert KC, Dietz R, von Harsdorf R; German Heart Failure Network. |
Circulation. 2006 Mar 7;113(9):1203-12. Epub 2006 Feb 27. |
PMID 16505176 |
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ARC inhibits cytochrome c release from mitochondria and protects against hypoxia-induced apoptosis in heart-derived H9c2 cells. |
Ekhterae D, Lin Z, Lundberg MS, Crow MT, Brosius FC 3rd, Nunez G. |
Circ Res. 1999 Dec 9;85(12):e70-7. |
PMID 10590251 |
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Alteration of caspases and apoptosis-related proteins in brains of patients with Alzheimer's disease. |
Engidawork E, Gulesserian T, Yoo BC, Cairns N, Lubec G. |
Biochem Biophys Res Commun. 2001 Feb 16;281(1):84-93. |
PMID 11178964 |
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Ubiquitination and degradation of the anti-apoptotic protein ARC by MDM2. |
Foo RS, Chan LK, Kitsis RN, Bennett MR. |
J Biol Chem. 2007 Feb 23;282(8):5529-35. Epub 2006 Dec 2. |
PMID 17142834 |
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Regulation of p53 tetramerization and nuclear export by ARC. |
Foo RS, Nam YJ, Ostreicher MJ, Metzl MD, Whelan RS, Peng CF, Ashton AW, Fu W, Mani K, Chin SF, Provenzano E, Ellis I, Figg N, Pinder S, Bennett MR, Caldas C, Kitsis RN. |
Proc Natl Acad Sci U S A. 2007 Dec 26;104(52):20826-31. Epub 2007 Dec 17. |
PMID 18087040 |
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Cloning and characterization of cDNAs for novel proteins with glutamic acid-proline dipeptide tandem repeats. |
Geertman R, McMahon A, Sabban EL. |
Biochim Biophys Acta. 1996 May 2;1306(2-3):147-52. |
PMID 8634331 |
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Apoptosis repressor with caspase recruitment domain protects against cell death by interfering with Bax activation. |
Gustafsson AB, Tsai JG, Logue SE, Crow MT, Gottlieb RA. |
J Biol Chem. 2004 May 14;279(20):21233-8. Epub 2004 Mar 5. |
PMID 15004034 |
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Caspase-8 and its inhibitors in RCCs in vivo: the prominent role of ARC. |
Heikaus S, Kempf T, Mahotka C, Gabbert HE, Ramp U. |
Apoptosis. 2008 Jul;13(7):938-49. |
PMID 18516683 |
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Down-regulation of ARC contributes to vulnerability of hippocampal neurons to ischemia/hypoxia. |
Hong YM, Jo DG, Lee JY, Chang JW, Nam JH, Noh JY, Koh JY, Jung YK. |
FEBS Lett. 2003 May 22;543(1-3):170-3. |
PMID 12753927 |
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ARC, an inhibitor of apoptosis expressed in skeletal muscle and heart that interacts selectively with caspases. |
Koseki T, Inohara N, Chen S, Nunez G. |
Proc Natl Acad Sci U S A. 1998 Apr 28;95(9):5156-60. |
PMID 9560245 |
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p53 initiates apoptosis by transcriptionally targeting the antiapoptotic protein ARC. |
Li YZ, Lu DY, Tan WQ, Wang JX, Li PF. |
Mol Cell Biol. 2008 Jan;28(2):564-74. Epub 2007 Nov 12. |
PMID 17998337 |
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ARC (apoptosis repressor with caspase recruitment domain) is a novel marker of human colon cancer. |
Mercier I, Vuolo M, Jasmin JF, Medina CM, Williams M, Mariadason JM, Qian H, Xue X, Pestell RG, Lisanti MP, Kitsis RN. |
Cell Cycle. 2008 Jun 1;7(11):1640-7. Epub 2008 Mar 19. |
PMID 18469522 |
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The apoptosis inhibitor ARC undergoes ubiquitin-proteasomal-mediated degradation in response to death stimuli: identification of a degradation-resistant mutant. |
Nam YJ, Mani K, Wu L, Peng CF, Calvert JW, Foo RS, Krishnamurthy B, Miao W, Ashton AW, Lefer DJ, Kitsis RN. |
J Biol Chem. 2007 Feb 23;282(8):5522-8. Epub 2006 Dec 1. |
PMID 17142452 |
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The apoptotic regulatory protein ARC (apoptosis repressor with caspase recruitment domain) prevents oxidant stress-mediated cell death by preserving mitochondrial function. |
Neuss M, Monticone R, Lundberg MS, Chesley AT, Fleck E, Crow MT. |
J Biol Chem. 2001 Sep 7;276(36):33915-22. Epub 2001 Jul 3. |
PMID 11438535 |
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Protection of cardiomyocytes from ischemic/hypoxic cell death via Drbp1 and pMe2GlyDH in cardio-specific ARC transgenic mice. |
Pyo JO, Nah J, Kim HJ, Chang JW, Song YW, Yang DK, Jo DG, Kim HR, Chae HJ, Chae SW, Hwang SY, Kim SJ, Kim HJ, Cho C, Oh CG, Park WJ, Jung YK. |
J Biol Chem. 2008 Nov 7;283(45):30707-14. Epub 2008 Sep 9. |
PMID 18782777 |
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Lifelong caloric restriction increases expression of apoptosis repressor with a caspase recruitment domain (ARC) in the brain. |
Shelke RR, Leeuwenburgh C. |
FASEB J. 2003 Mar;17(3):494-6. Epub 2003 Jan 2. |
PMID 12514107 |
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Alternative splicing determines the intracellular localization of the novel nuclear protein Nop30 and its interaction with the splicing factor SRp30c. |
Stoss O, Schwaiger FW, Cooper TA, Stamm S. |
J Biol Chem. 1999 Apr 16;274(16):10951-62. |
PMID 10196175 |
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Novel cardiac apoptotic pathway: the dephosphorylation of apoptosis repressor with caspase recruitment domain by calcineurin. |
Tan WQ, Wang JX, Lin ZQ, Li YR, Lin Y, Li PF. |
Circulation. 2008 Nov 25;118(22):2268-76. Epub 2008 Nov 10. |
PMID 19001025 |
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Apoptosis repressor with caspase recruitment domain contributes to chemotherapy resistance by abolishing mitochondrial fission mediated by dynamin-related protein-1. |
Wang JX, Li Q, Li PF. |
Cancer Res. 2009 Jan 15;69(2):492-500. |
PMID 19147562 |
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