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Protein

Complement component C8 alpha chain

Gene

C8A

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Constituent of the membrane attack complex (MAC) that plays a key role in the innate and adaptive immune response by forming pores in the plasma membrane of target cells. C8A inserts into the target membrane, but does not form pores by itself.2 Publications

GO - Molecular functioni

GO - Biological processi

  • complement activation Source: MGI
  • complement activation, alternative pathway Source: UniProtKB-KW
  • complement activation, classical pathway Source: UniProtKB-KW
  • cytolysis Source: UniProtKB-KW
  • immune response Source: ProtInc
  • regulation of complement activation Source: Reactome

Keywordsi

Biological processComplement alternate pathway, Complement pathway, Cytolysis, Immunity, Innate immunity

Enzyme and pathway databases

ReactomeiR-HSA-166665 Terminal pathway of complement
R-HSA-977606 Regulation of Complement cascade

Protein family/group databases

TCDBi1.C.39.3.1 the membrane attack complex/perforin (macpf) family

Names & Taxonomyi

Protein namesi
Recommended name:
Complement component C8 alpha chain
Alternative name(s):
Complement component 8 subunit alpha
Gene namesi
Name:C8A
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 1

Organism-specific databases

EuPathDBiHostDB:ENSG00000157131.10
HGNCiHGNC:1352 C8A
MIMi120950 gene
neXtProtiNX_P07357

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Cell membrane, Membrane, Membrane attack complex, Secreted

Pathology & Biotechi

Involvement in diseasei

Complement component 8 deficiency, 1 (C8D1)
Disease susceptibility is associated with variations affecting the gene represented in this entry.
Disease descriptionA rare defect of the complement classical pathway associated with susceptibility to severe recurrent infections, predominantly by Neisseria gonorrhoeae or Neisseria meningitidis.
See also OMIM:613790

Organism-specific databases

DisGeNETi731
MalaCardsiC8A
MIMi613790 phenotype
OpenTargetsiENSG00000157131
Orphaneti169150 Immunodeficiency due to a late component of complements deficiency
PharmGKBiPA25951

Polymorphism and mutation databases

BioMutaiC8A
DMDMi729167

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 20Sequence analysisAdd BLAST20
PropeptideiPRO_000002358521 – 30Sequence analysis10
ChainiPRO_000002358631 – 584Complement component C8 alpha chainAdd BLAST554

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi39 ↔ 74By similarity
Glycosylationi44C-linked (Man) tryptophan1 Publication1
Disulfide bondi50 ↔ 53By similarity
Disulfide bondi84 ↔ 90By similarity
Disulfide bondi96 ↔ 108By similarity
Disulfide bondi102 ↔ 121By similarity
Disulfide bondi115 ↔ 130By similarity
Disulfide bondi140 ↔ 177
Disulfide bondi194Interchain (with C-60 in C8-gamma chain)
Disulfide bondi375 ↔ 399
Glycosylationi437N-linked (GlcNAc...) asparagine2 Publications1
Glycosylationi542C-linked (Man) tryptophan1 Publication1
Glycosylationi545C-linked (Man) tryptophan1 Publication1
Glycosylationi548C-linked (Man) tryptophan1 Publication1

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei43Not glycosylated1

Keywords - PTMi

Cleavage on pair of basic residues, Disulfide bond, Glycoprotein

Proteomic databases

MaxQBiP07357
PaxDbiP07357
PeptideAtlasiP07357
PRIDEiP07357
ProteomicsDBi51997

PTM databases

iPTMnetiP07357
PhosphoSitePlusiP07357

Expressioni

Gene expression databases

BgeeiENSG00000157131 Expressed in 33 organ(s), highest expression level in right lobe of liver
CleanExiHS_C8A
GenevisibleiP07357 HS

Interactioni

Subunit structurei

Heterotrimer of 3 chains: alpha, beta and gamma. The alpha and gamma chains are disulfide bonded. Component of the membrane attack complex (MAC). MAC assembly is initiated by proteolytic cleavage of C5 into C5a and C5b. C5b sequentially binds C6, C7, C8 and multiple copies of the pore-forming subunit C9.3 Publications

GO - Molecular functioni

Protein-protein interaction databases

BioGridi107192, 13 interactors
DIPiDIP-1125N
IntActiP07357, 2 interactors
STRINGi9606.ENSP00000354458

Structurei

Secondary structure

1584
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details

3D structure databases

ProteinModelPortaliP07357
SMRiP07357
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP07357

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini38 – 91TSP type-1 1PROSITE-ProRule annotationAdd BLAST54
Domaini94 – 132LDL-receptor class APROSITE-ProRule annotationAdd BLAST39
Domaini135 – 498MACPFPROSITE-ProRule annotationAdd BLAST364
Domaini499 – 529EGF-likeAdd BLAST31
Domaini539 – 583TSP type-1 2PROSITE-ProRule annotationAdd BLAST45

Sequence similaritiesi

Belongs to the complement C6/C7/C8/C9 family.Curated

Keywords - Domaini

EGF-like domain, Repeat, Signal, Transmembrane, Transmembrane beta strand

Phylogenomic databases

eggNOGiENOG410IE8U Eukaryota
ENOG410Y5MF LUCA
GeneTreeiENSGT00550000074478
HOGENOMiHOG000231146
HOVERGENiHBG005368
InParanoidiP07357
KOiK03997
OMAiACRCGPC
OrthoDBiEOG091G07LK
PhylomeDBiP07357
TreeFamiTF330498

Family and domain databases

CDDicd00112 LDLa, 1 hit
Gene3Di2.20.100.10, 2 hits
InterProiView protein in InterPro
IPR037565 Complement_C8_alpha
IPR009030 Growth_fac_rcpt_cys_sf
IPR023415 LDLR_class-A_CS
IPR002172 LDrepeatLR_classA_rpt
IPR001862 MAC_perforin
IPR020864 MACPF
IPR020863 MACPF_CS
IPR000884 TSP1_rpt
IPR036383 TSP1_rpt_sf
PANTHERiPTHR19325:SF385 PTHR19325:SF385, 1 hit
PfamiView protein in Pfam
PF00057 Ldl_recept_a, 1 hit
PF01823 MACPF, 1 hit
PF00090 TSP_1, 1 hit
PRINTSiPR00764 COMPLEMENTC9
SMARTiView protein in SMART
SM00192 LDLa, 1 hit
SM00457 MACPF, 1 hit
SM00209 TSP1, 2 hits
SUPFAMiSSF57184 SSF57184, 3 hits
SSF82895 SSF82895, 2 hits
PROSITEiView protein in PROSITE
PS00022 EGF_1, 1 hit
PS01209 LDLRA_1, 1 hit
PS50068 LDLRA_2, 1 hit
PS00279 MACPF_1, 1 hit
PS51412 MACPF_2, 1 hit
PS50092 TSP1, 2 hits

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P07357-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MFAVVFFILS LMTCQPGVTA QEKVNQRVRR AATPAAVTCQ LSNWSEWTDC
60 70 80 90 100
FPCQDKKYRH RSLLQPNKFG GTICSGDIWD QASCSSSTTC VRQAQCGQDF
110 120 130 140 150
QCKETGRCLK RHLVCNGDQD CLDGSDEDDC EDVRAIDEDC SQYEPIPGSQ
160 170 180 190 200
KAALGYNILT QEDAQSVYDA SYYGGQCETV YNGEWRELRY DSTCERLYYG
210 220 230 240 250
DDEKYFRKPY NFLKYHFEAL ADTGISSEFY DNANDLLSKV KKDKSDSFGV
260 270 280 290 300
TIGIGPAGSP LLVGVGVSHS QDTSFLNELN KYNEKKFIFT RIFTKVQTAH
310 320 330 340 350
FKMRKDDIML DEGMLQSLME LPDQYNYGMY AKFINDYGTH YITSGSMGGI
360 370 380 390 400
YEYILVIDKA KMESLGITSR DITTCFGGSL GIQYEDKINV GGGLSGDHCK
410 420 430 440 450
KFGGGKTERA RKAMAVEDII SRVRGGSSGW SGGLAQNRST ITYRSWGRSL
460 470 480 490 500
KYNPVVIDFE MQPIHEVLRH TSLGPLEAKR QNLRRALDQY LMEFNACRCG
510 520 530 540 550
PCFNNGVPIL EGTSCRCQCR LGSLGAACEQ TQTEGAKADG SWSCWSSWSV
560 570 580
CRAGIQERRR ECDNPAPQNG GASCPGRKVQ TQAC
Length:584
Mass (Da):65,163
Last modified:February 1, 1995 - v2
Checksum:i9F61DDA51D2F3BBA
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti575P → S in AAA82124 (PubMed:7759071).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_01188993Q → K in allele C8A*B. 2 PublicationsCorresponds to variant dbSNP:rs652785EnsemblClinVar.1
Natural variantiVAR_011890407T → I. Corresponds to variant dbSNP:rs706479Ensembl.1
Natural variantiVAR_033800458D → N. Corresponds to variant dbSNP:rs17114555Ensembl.1
Natural variantiVAR_011891485R → L. Corresponds to variant dbSNP:rs1620075EnsemblClinVar.1
Natural variantiVAR_011892561E → Q. Corresponds to variant dbSNP:rs1342440EnsemblClinVar.1
Natural variantiVAR_033801575P → L. Corresponds to variant dbSNP:rs17300936Ensembl.1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M16974 mRNA Translation: AAA52200.1
U08006
, U07996, U07997, U07998, U07999, U08000, U08001, U08002, U08003, U08004, U08005 Genomic DNA Translation: AAA82124.1
AL121998 Genomic DNA No translation available.
BC132911 mRNA Translation: AAI32912.1
BC132913 mRNA Translation: AAI32914.1
CCDSiCCDS606.1
PIRiI37213 C8HUA
RefSeqiNP_000553.1, NM_000562.2
UniGeneiHs.93210

Genome annotation databases

EnsembliENST00000361249; ENSP00000354458; ENSG00000157131
GeneIDi731
KEGGihsa:731
UCSCiuc001cyo.3 human

Keywords - Coding sequence diversityi

Polymorphism

Similar proteinsi

Entry informationi

Entry nameiCO8A_HUMAN
AccessioniPrimary (citable) accession number: P07357
Secondary accession number(s): A2RUI4
, A2RUI5, Q13668, Q9H130
Entry historyiIntegrated into UniProtKB/Swiss-Prot: April 1, 1988
Last sequence update: February 1, 1995
Last modified: September 12, 2018
This is version 195 of the entry and version 2 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Direct protein sequencing, Reference proteome
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health

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