Complement component 1 Q subcomponent-binding protein, mitochondrial


Complement component 1 Q subcomponent-binding protein, mitochondrial
  • ASF/SF2-associated protein p32
  • C1qBP
  • gC1q-R protein
  • GC1QBP
  • Glycoprotein gC1qBP
  • HABP1
  • Hyaluronan-binding protein 1
  • Mitochondrial matrix protein p32
  • p33
  • SF2P32
Gene Name
Amino acid sequence
>lcl|BSEQ0019649|Complement component 1 Q subcomponent-binding protein, mitochondrial
Number of residues
Molecular Weight
Theoretical pI
Not Available
GO Classification
adrenergic receptor binding / complement component C1q binding / hyaluronic acid binding / kininogen binding / mitochondrial ribosome binding / mRNA binding / transcription corepressor activity / transcription factor binding
apoptotic process / blood coagulation / blood coagulation, intrinsic pathway / complement activation, classical pathway / immune response / innate immune response / mature ribosome assembly / mRNA processing / negative regulation of defense response to virus / negative regulation of interferon-gamma production / negative regulation of interleukin-12 production / negative regulation of MDA-5 signaling pathway / negative regulation of mRNA splicing, via spliceosome / negative regulation of RIG-I signaling pathway / negative regulation of transcription from RNA polymerase II promoter / phosphatidylinositol 3-kinase signaling / positive regulation of apoptotic process / positive regulation of cell adhesion / positive regulation of dendritic cell chemotaxis / positive regulation of mitochondrial translation / positive regulation of neutrophil chemotaxis / positive regulation of protein kinase B signaling / positive regulation of substrate adhesion-dependent cell spreading / positive regulation of trophoblast cell migration / regulation of complement activation / RNA splicing / transcription, DNA-templated / viral process
cell surface / cytoplasm / cytosol / extracellular space / membrane / mitochondrial matrix / mitochondrion / nucleolus / nucleus / plasma membrane
General Function
Transcription factor binding
Specific Function
Is believed to be a multifunctional and multicompartmental protein involved in inflammation and infection processes, ribosome biogenesis, regulation of apoptosis, transcriptional regulation and pre-mRNA splicing. At the cell surface is thought to act as an endothelial receptor for plasma proteins of the complement and kallikrein-kinin cascades. Putative receptor for C1q; specifically binds to the globular "heads" of C1q thus inhibiting C1; may perform the receptor function through a complex with C1qR/CD93. In complex with cytokeratin-1/KRT1 is a high affinity receptor for kininogen-1/HMWK. Can also bind other plasma proteins, such as coagulation factor XII leading to its autoactivation. May function to bind initially fluid kininogen-1 to the cell membrane. The secreted form may enhance both extrinsic and intrinsic coagulation pathways. It is postulated that the cell surface form requires docking with transmembrane proteins for downstream signaling which might be specific for a cell-type or response. By acting as C1q receptor is involved in chemotaxis of immature dendritic cells and neutrophils and is proposed to signal through CD209/DC-SIGN on immature dendritic cells, through integrin alpha-4/beta-1 during trophoblast invasion of the decidua, and through integrin beta-1 during endothelial cell adhesion and spreading. Signaling involved in inhibition of innate immune response is implicating the PI3K-AKT/PKB pathway. In mitochondrial translation may be involved in formation of functional 55S mitoribosomes; the function seems to involve its RNA-binding activity. May be involved in the nucleolar ribosome maturation process; the function may involve the exchange of FBL for RRP1 in the association with pre-ribosome particles. Involved in regulation of RNA splicing by inhibiting the RNA-binding capacity of SRSF1 and its phosphorylation. Is required for the nuclear translocation of splicing factor U2AF1L4. Involved in regulation of CDKN2A- and HRK-mediated apoptosis. Stabilizes mitochondrial CDKN2A isoform smARF. May be involved in regulation of FOXC1 transcriptional activity and NFY/CCAAT-binding factor complex-mediated transcription. In infection processes acts as an attachment site for microbial proteins, including Listeria monocytogenes internalin B and Staphylococcus aureus protein A. May play a role in antibacterial defense as it can bind to cell surface hyaluronan and inhibit Streptococcus pneumoniae hyaluronate lyase. Involved in replication of Rubella virus. May be involved in modulation of the immune response; ligation by HCV core protein is resulting in suppresion of interleukin-12 production in monocyte-derived dendritic cells. Involved in regulation of antiviral response by inhibiting DDX58- and IFIH1-mediated signaling pathways probably involving its association with MAVS after viral infection. Involved in HIV-1 replication, presumably by contributing to splicing of viral RNA.
Pfam Domain Function
Transmembrane Regions
Not Available
Cellular Location
Mitochondrion matrix
Gene sequence
>lcl|BSEQ0019650|Complement component 1 Q subcomponent-binding protein, mitochondrial (C1QBP)
Chromosome Location
Not Available
External Identifiers
UniProtKB IDQ07021
UniProtKB Entry NameC1QBP_HUMAN
General References
  1. Honore B, Madsen P, Rasmussen HH, Vandekerckhove J, Celis JE, Leffers H: Cloning and expression of a cDNA covering the complete coding region of the P32 subunit of human pre-mRNA splicing factor SF2. Gene. 1993 Dec 8;134(2):283-7. [Article]
  2. Ghebrehiwet B, Lim BL, Peerschke EI, Willis AC, Reid KB: Isolation, cDNA cloning, and overexpression of a 33-kD cell surface glycoprotein that binds to the globular "heads" of C1q. J Exp Med. 1994 Jun 1;179(6):1809-21. [Article]
  3. Tye AJ, Ghebrehiwet B, Guo N, Sastry KN, Chow BK, Peerschke EI, Lim BL: The human gC1qR/p32 gene, C1qBP. Genomic organization and promoter analysis. J Biol Chem. 2001 May 18;276(20):17069-75. Epub 2001 Mar 8. [Article]
  4. Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield YS, Griffith M, Griffith OL, Krzywinski MI, Liao N, Morin R, Palmquist D, Petrescu AS, Skalska U, Smailus DE, Stott JM, Schnerch A, Schein JE, Jones SJ, Holt RA, Baross A, Marra MA, Clifton S, Makowski KA, Bosak S, Malek J: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome Res. 2004 Oct;14(10B):2121-7. [Article]
  5. Krainer AR, Mayeda A, Kozak D, Binns G: Functional expression of cloned human splicing factor SF2: homology to RNA-binding proteins, U1 70K, and Drosophila splicing regulators. Cell. 1991 Jul 26;66(2):383-94. [Article]
  6. Herwald H, Dedio J, Kellner R, Loos M, Muller-Esterl W: Isolation and characterization of the kininogen-binding protein p33 from endothelial cells. Identity with the gC1q receptor. J Biol Chem. 1996 May 31;271(22):13040-7. [Article]
  7. Deb TB, Datta K: Molecular cloning of human fibroblast hyaluronic acid-binding protein confirms its identity with P-32, a protein co-purified with splicing factor SF2. Hyaluronic acid-binding protein as P-32 protein, co-purified with splicing factor SF2. J Biol Chem. 1996 Jan 26;271(4):2206-12. [Article]
  8. Lim BL, Reid KB, Ghebrehiwet B, Peerschke EI, Leigh LA, Preissner KT: The binding protein for globular heads of complement C1q, gC1qR. Functional expression and characterization as a novel vitronectin binding factor. J Biol Chem. 1996 Oct 25;271(43):26739-44. [Article]
  9. Joseph K, Ghebrehiwet B, Peerschke EI, Reid KB, Kaplan AP: Identification of the zinc-dependent endothelial cell binding protein for high molecular weight kininogen and factor XII: identity with the receptor that binds to the globular "heads" of C1q (gC1q-R). Proc Natl Acad Sci U S A. 1996 Aug 6;93(16):8552-7. [Article]
  10. Peterson KL, Zhang W, Lu PD, Keilbaugh SA, Peerschke EI, Ghebrehiwet B: The C1q-binding cell membrane proteins cC1q-R and gC1q-R are released from activated cells: subcellular distribution and immunochemical characterization. Clin Immunol Immunopathol. 1997 Jul;84(1):17-26. [Article]
  11. Muta T, Kang D, Kitajima S, Fujiwara T, Hamasaki N: p32 protein, a splicing factor 2-associated protein, is localized in mitochondrial matrix and is functionally important in maintaining oxidative phosphorylation. J Biol Chem. 1997 Sep 26;272(39):24363-70. [Article]
  12. Ghebrehiwet B, Lu PD, Zhang W, Keilbaugh SA, Leigh LE, Eggleton P, Reid KB, Peerschke EI: Evidence that the two C1q binding membrane proteins, gC1q-R and cC1q-R, associate to form a complex. J Immunol. 1997 Aug 1;159(3):1429-36. [Article]
  13. Leigh LE, Ghebrehiwet B, Perera TP, Bird IN, Strong P, Kishore U, Reid KB, Eggleton P: C1q-mediated chemotaxis by human neutrophils: involvement of gClqR and G-protein signalling mechanisms. Biochem J. 1998 Feb 15;330 ( Pt 1):247-54. [Article]
  14. Joseph K, Ghebrehiwet B, Kaplan AP: Cytokeratin 1 and gC1qR mediate high molecular weight kininogen binding to endothelial cells. Clin Immunol. 1999 Sep;92(3):246-55. [Article]
  15. Petersen-Mahrt SK, Estmer C, Ohrmalm C, Matthews DA, Russell WC, Akusjarvi G: The splicing factor-associated protein, p32, regulates RNA splicing by inhibiting ASF/SF2 RNA binding and phosphorylation. EMBO J. 1999 Feb 15;18(4):1014-24. [Article]
  16. Braun L, Ghebrehiwet B, Cossart P: gC1q-R/p32, a C1q-binding protein, is a receptor for the InlB invasion protein of Listeria monocytogenes. EMBO J. 2000 Apr 3;19(7):1458-66. [Article]
  17. Nguyen T, Ghebrehiwet B, Peerschke EI: Staphylococcus aureus protein A recognizes platelet gC1qR/p33: a novel mechanism for staphylococcal interactions with platelets. Infect Immun. 2000 Apr;68(4):2061-8. [Article]
  18. Kittlesen DJ, Chianese-Bullock KA, Yao ZQ, Braciale TJ, Hahn YS: Interaction between complement receptor gC1qR and hepatitis C virus core protein inhibits T-lymphocyte proliferation. J Clin Invest. 2000 Nov;106(10):1239-49. [Article]
  19. Beatch MD, Hobman TC: Rubella virus capsid associates with host cell protein p32 and localizes to mitochondria. J Virol. 2000 Jun;74(12):5569-76. [Article]
  20. van Leeuwen HC, O'Hare P: Retargeting of the mitochondrial protein p32/gC1Qr to a cytoplasmic compartment and the cell surface. J Cell Sci. 2001 Jun;114(Pt 11):2115-23. [Article]
  21. Feng X, Tonnesen MG, Peerschke EI, Ghebrehiwet B: Cooperation of C1q receptors and integrins in C1q-mediated endothelial cell adhesion and spreading. J Immunol. 2002 Mar 1;168(5):2441-8. [Article]
  22. Mohan KV, Ghebrehiwet B, Atreya CD: The N-terminal conserved domain of rubella virus capsid interacts with the C-terminal region of cellular p32 and overexpression of p32 enhances the viral infectivity. Virus Res. 2002 May 10;85(2):151-61. [Article]
  23. Zheng YH, Yu HF, Peterlin BM: Human p32 protein relieves a post-transcriptional block to HIV replication in murine cells. Nat Cell Biol. 2003 Jul;5(7):611-8. [Article]
  24. Peerschke EI, Murphy TK, Ghebrehiwet B: Activation-dependent surface expression of gC1qR/p33 on human blood platelets. Thromb Haemost. 2003 Feb;89(2):331-9. [Article]
  25. Sunayama J, Ando Y, Itoh N, Tomiyama A, Sakurada K, Sugiyama A, Kang D, Tashiro F, Gotoh Y, Kuchino Y, Kitanaka C: Physical and functional interaction between BH3-only protein Hrk and mitochondrial pore-forming protein p32. Cell Death Differ. 2004 Jul;11(7):771-81. [Article]
  26. Chattopadhyay C, Hawke D, Kobayashi R, Maity SN: Human p32, interacts with B subunit of the CCAAT-binding factor, CBF/NF-Y, and inhibits CBF-mediated transcription activation in vitro. Nucleic Acids Res. 2004 Jul 8;32(12):3632-41. Print 2004. [Article]
  27. Waggoner SN, Cruise MW, Kassel R, Hahn YS: gC1q receptor ligation selectively down-regulates human IL-12 production through activation of the phosphoinositide 3-kinase pathway. J Immunol. 2005 Oct 1;175(7):4706-14. [Article]
  28. Even Y, Durieux S, Escande ML, Lozano JC, Peaucellier G, Weil D, Geneviere AM: CDC2L5, a Cdk-like kinase with RS domain, interacts with the ASF/SF2-associated protein p32 and affects splicing in vivo. J Cell Biochem. 2006 Oct 15;99(3):890-904. [Article]
  29. Berro R, Kehn K, de la Fuente C, Pumfery A, Adair R, Wade J, Colberg-Poley AM, Hiscott J, Kashanchi F: Acetylated Tat regulates human immunodeficiency virus type 1 splicing through its interaction with the splicing regulator p32. J Virol. 2006 Apr;80(7):3189-204. [Article]
  30. Vegh Z, Kew RR, Gruber BL, Ghebrehiwet B: Chemotaxis of human monocyte-derived dendritic cells to complement component C1q is mediated by the receptors gC1qR and cC1qR. Mol Immunol. 2006 Mar;43(9):1402-7. Epub 2005 Sep 2. [Article]
  31. Waggoner SN, Hall CH, Hahn YS: HCV core protein interaction with gC1q receptor inhibits Th1 differentiation of CD4+ T cells via suppression of dendritic cell IL-12 production. J Leukoc Biol. 2007 Dec;82(6):1407-19. Epub 2007 Sep 19. [Article]
  32. Tang LY, Deng N, Wang LS, Dai J, Wang ZL, Jiang XS, Li SJ, Li L, Sheng QH, Wu DQ, Li L, Zeng R: Quantitative phosphoproteome profiling of Wnt3a-mediated signaling network: indicating the involvement of ribonucleoside-diphosphate reductase M2 subunit phosphorylation at residue serine 20 in canonical Wnt signal transduction. Mol Cell Proteomics. 2007 Nov;6(11):1952-67. Epub 2007 Aug 12. [Article]
  33. Reef S, Shifman O, Oren M, Kimchi A: The autophagic inducer smARF interacts with and is stabilized by the mitochondrial p32 protein. Oncogene. 2007 Oct 11;26(46):6677-83. Epub 2007 May 7. [Article]
  34. Huang L, Chi J, Berry FB, Footz TK, Sharp MW, Walter MA: Human p32 is a novel FOXC1-interacting protein that regulates FOXC1 transcriptional activity in ocular cells. Invest Ophthalmol Vis Sci. 2008 Dec;49(12):5243-9. doi: 10.1167/iovs.07-1625. Epub 2008 Aug 1. [Article]
  35. Dephoure N, Zhou C, Villen J, Beausoleil SA, Bakalarski CE, Elledge SJ, Gygi SP: A quantitative atlas of mitotic phosphorylation. Proc Natl Acad Sci U S A. 2008 Aug 5;105(31):10762-7. doi: 10.1073/pnas.0805139105. Epub 2008 Jul 31. [Article]
  36. Yadav G, Prasad RL, Jha BK, Rai V, Bhakuni V, Datta K: Evidence for inhibitory interaction of hyaluronan-binding protein 1 (HABP1/p32/gC1qR) with Streptococcus pneumoniae hyaluronidase. J Biol Chem. 2009 Feb 6;284(6):3897-905. doi: 10.1074/jbc.M804246200. Epub 2008 Nov 11. [Article]
  37. Xu L, Xiao N, Liu F, Ren H, Gu J: Inhibition of RIG-I and MDA5-dependent antiviral response by gC1qR at mitochondria. Proc Natl Acad Sci U S A. 2009 Feb 3;106(5):1530-5. doi: 10.1073/pnas.0811029106. Epub 2009 Jan 21. [Article]
  38. Mayya V, Lundgren DH, Hwang SI, Rezaul K, Wu L, Eng JK, Rodionov V, Han DK: Quantitative phosphoproteomic analysis of T cell receptor signaling reveals system-wide modulation of protein-protein interactions. Sci Signal. 2009 Aug 18;2(84):ra46. doi: 10.1126/scisignal.2000007. [Article]
  39. Choudhary C, Kumar C, Gnad F, Nielsen ML, Rehman M, Walther TC, Olsen JV, Mann M: Lysine acetylation targets protein complexes and co-regulates major cellular functions. Science. 2009 Aug 14;325(5942):834-40. doi: 10.1126/science.1175371. Epub 2009 Jul 16. [Article]
  40. Agostinis C, Bulla R, Tripodo C, Gismondi A, Stabile H, Bossi F, Guarnotta C, Garlanda C, De Seta F, Spessotto P, Santoni A, Ghebrehiwet B, Girardi G, Tedesco F: An alternative role of C1q in cell migration and tissue remodeling: contribution to trophoblast invasion and placental development. J Immunol. 2010 Oct 1;185(7):4420-9. doi: 10.4049/jimmunol.0903215. Epub 2010 Sep 1. [Article]
  41. Burkard TR, Planyavsky M, Kaupe I, Breitwieser FP, Burckstummer T, Bennett KL, Superti-Furga G, Colinge J: Initial characterization of the human central proteome. BMC Syst Biol. 2011 Jan 26;5:17. doi: 10.1186/1752-0509-5-17. [Article]
  42. McGee AM, Baines CP: Complement 1q-binding protein inhibits the mitochondrial permeability transition pore and protects against oxidative stress-induced death. Biochem J. 2011 Jan 1;433(1):119-25. doi: 10.1042/BJ20101431. [Article]
  43. Yoshikawa H, Komatsu W, Hayano T, Miura Y, Homma K, Izumikawa K, Ishikawa H, Miyazawa N, Tachikawa H, Yamauchi Y, Isobe T, Takahashi N: Splicing factor 2-associated protein p32 participates in ribosome biogenesis by regulating the binding of Nop52 and fibrillarin to preribosome particles. Mol Cell Proteomics. 2011 Aug;10(8):M110.006148. doi: 10.1074/mcp.M110.006148. Epub 2011 May 2. [Article]
  44. Pixley RA, Espinola RG, Ghebrehiwet B, Joseph K, Kao A, Bdeir K, Cines DB, Colman RW: Interaction of high-molecular-weight kininogen with endothelial cell binding proteins suPAR, gC1qR and cytokeratin 1 determined by surface plasmon resonance (BiaCore). Thromb Haemost. 2011 Jun;105(6):1053-9. doi: 10.1160/TH10-09-0591. Epub 2011 May 5. [Article]
  45. Hosszu KK, Valentino A, Vinayagasundaram U, Vinayagasundaram R, Joyce MG, Ji Y, Peerschke EI, Ghebrehiwet B: DC-SIGN, C1q, and gC1qR form a trimolecular receptor complex on the surface of monocyte-derived immature dendritic cells. Blood. 2012 Aug 9;120(6):1228-36. doi: 10.1182/blood-2011-07-369728. Epub 2012 Jun 13. [Article]
  46. Suppiah S, Mousa HA, Tzeng WP, Matthews JD, Frey TK: Binding of cellular p32 protein to the rubella virus P150 replicase protein via PxxPxR motifs. J Gen Virol. 2012 Apr;93(Pt 4):807-16. doi: 10.1099/vir.0.038901-0. Epub 2012 Jan 13. [Article]
  47. Bian Y, Song C, Cheng K, Dong M, Wang F, Huang J, Sun D, Wang L, Ye M, Zou H: An enzyme assisted RP-RPLC approach for in-depth analysis of human liver phosphoproteome. J Proteomics. 2014 Jan 16;96:253-62. doi: 10.1016/j.jprot.2013.11.014. Epub 2013 Nov 22. [Article]
  48. Vaca Jacome AS, Rabilloud T, Schaeffer-Reiss C, Rompais M, Ayoub D, Lane L, Bairoch A, Van Dorsselaer A, Carapito C: N-terminome analysis of the human mitochondrial proteome. Proteomics. 2015 Jul;15(14):2519-24. doi: 10.1002/pmic.201400617. Epub 2015 Jun 8. [Article]
  49. Jiang J, Zhang Y, Krainer AR, Xu RM: Crystal structure of human p32, a doughnut-shaped acidic mitochondrial matrix protein. Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):3572-7. [Article]

Drug Relations

Drug Relations
DrugBank IDNameDrug groupPharmacological action?ActionsDetails
DB08818Hyaluronic acidapproved, vet_approvedunknownbinderDetails
DB09130Copperapproved, investigationalunknownDetails