P04003 · C4BPA_HUMAN
- ProteinC4b-binding protein alpha chain
- GeneC4BPA
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids597 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Controls the classical pathway of complement activation. It binds as a cofactor to C3b/C4b inactivator (C3bINA), which then hydrolyzes the complement fragment C4b. It also accelerates the degradation of the C4bC2a complex (C3 convertase) by dissociating the complement fragment C2a. Alpha chain binds C4b. It interacts also with anticoagulant protein S and with serum amyloid P component.
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | blood microparticle | |
Cellular Component | extracellular region | |
Cellular Component | extracellular space | |
Cellular Component | plasma membrane | |
Molecular Function | RNA binding | |
Biological Process | complement activation, classical pathway | |
Biological Process | innate immune response | |
Biological Process | negative regulation of complement activation, classical pathway | |
Biological Process | positive regulation of protein catabolic process | |
Biological Process | regulation of opsonization | |
Biological Process | response to symbiotic bacterium | |
Biological Process | T cell mediated immunity |
Keywords
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameC4b-binding protein alpha chain
- Short namesC4bp
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionP04003
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
Disease & Variants
Features
Showing features for natural variant.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | VAR_061123 | 4 | in dbSNP:rs55867570 | |||
Sequence: P → Q | ||||||
Natural variant | VAR_048815 | 60 | in dbSNP:rs17020956 | |||
Sequence: A → V | ||||||
Natural variant | VAR_061124 | 240 | in dbSNP:rs45574833 | |||
Sequence: R → H | ||||||
Natural variant | VAR_024420 | 300 | in dbSNP:rs4844573 | |||
Sequence: I → T | ||||||
Natural variant | VAR_001978 | 357 | ||||
Sequence: Y → H | ||||||
Natural variant | VAR_012038 | 473 | in dbSNP:rs1801341 | |||
Sequence: W → L |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 593 variants from UniProt as well as other sources including ClinVar and dbSNP.
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for signal, chain, disulfide bond, modified residue (large scale data), glycosylation.
Type | ID | Position(s) | Source | Description | |||
---|---|---|---|---|---|---|---|
Signal | 1-48 | UniProt | |||||
Sequence: MHPPKTPSGALHRKRKMAAWPFSRLWKVSDPILFQMTLIAALLPAVLG | |||||||
Chain | PRO_0000005888 | 49-597 | UniProt | C4b-binding protein alpha chain | |||
Sequence: NCGPPPTLSFAAPMDITLTETRFKTGTTLKYTCLPGYVRSHSTQTLTCNSDGEWVYNTFCIYKRCRHPGELRNGQVEIKTDLSFGSQIEFSCSEGFFLIGSTTSRCEVQDRGVGWSHPLPQCEIVKCKPPPDIRNGRHSGEENFYAYGFSVTYSCDPRFSLLGHASISCTVENETIGVWRPSPPTCEKITCRKPDVSHGEMVSGFGPIYNYKDTIVFKCQKGFVLRGSSVIHCDADSKWNPSPPACEPNSCINLPDIPHASWETYPRPTKEDVYVVGTVLRYRCHPGYKPTTDEPTTVICQKNLRWTPYQGCEALCCPEPKLNNGEITQHRKSRPANHCVYFYGDEISFSCHETSRFSAICQGDGTWSPRTPSCGDICNFPPKIAHGHYKQSSSYSFFKEEIIYECDKGYILVGQAKLSCSYSHWSAPAPQCKALCRKPELVNGRLSVDKDQYVEPENVTIQCDSGYGVVGPQSITCSGNRTWYPEVPKCEWETPEGCEQVLTGKRLMQCLPNPEDVKMALEVYKLSLEIEQLELQRDSARQSTLDKEL | |||||||
Disulfide bond | 50↔96 | UniProt | |||||
Sequence: CGPPPTLSFAAPMDITLTETRFKTGTTLKYTCLPGYVRSHSTQTLTC | |||||||
Disulfide bond | 81↔108 | UniProt | |||||
Sequence: CLPGYVRSHSTQTLTCNSDGEWVYNTFC | |||||||
Disulfide bond | 113↔154 | UniProt | |||||
Sequence: CRHPGELRNGQVEIKTDLSFGSQIEFSCSEGFFLIGSTTSRC | |||||||
Disulfide bond | 140↔170 | UniProt | |||||
Sequence: CSEGFFLIGSTTSRCEVQDRGVGWSHPLPQC | |||||||
Disulfide bond | 175↔217 | UniProt | |||||
Sequence: CKPPPDIRNGRHSGEENFYAYGFSVTYSCDPRFSLLGHASISC | |||||||
Modified residue (large scale data) | 187 | PRIDE | Phosphoserine | ||||
Sequence: S | |||||||
Disulfide bond | 203↔234 | UniProt | |||||
Sequence: CDPRFSLLGHASISCTVENETIGVWRPSPPTC | |||||||
Glycosylation | 221 | UniProt | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | |||||||
Disulfide bond | 239↔281 | UniProt | |||||
Sequence: CRKPDVSHGEMVSGFGPIYNYKDTIVFKCQKGFVLRGSSVIHC | |||||||
Disulfide bond | 267↔294 | UniProt | |||||
Sequence: CQKGFVLRGSSVIHCDADSKWNPSPPAC | |||||||
Disulfide bond | 299↔348 | UniProt | |||||
Sequence: CINLPDIPHASWETYPRPTKEDVYVVGTVLRYRCHPGYKPTTDEPTTVIC | |||||||
Disulfide bond | 332↔360 | UniProt | |||||
Sequence: CHPGYKPTTDEPTTVICQKNLRWTPYQGC | |||||||
Disulfide bond | 365↔409 | UniProt | |||||
Sequence: CPEPKLNNGEITQHRKSRPANHCVYFYGDEISFSCHETSRFSAIC | |||||||
Disulfide bond | 399↔422 | UniProt | |||||
Sequence: CHETSRFSAICQGDGTWSPRTPSC | |||||||
Disulfide bond | 426↔468 | UniProt | |||||
Sequence: CNFPPKIAHGHYKQSSSYSFFKEEIIYECDKGYILVGQAKLSC | |||||||
Disulfide bond | 454↔480 | UniProt | |||||
Sequence: CDKGYILVGQAKLSCSYSHWSAPAPQC | |||||||
Disulfide bond | 484↔525 | UniProt | |||||
Sequence: CRKPELVNGRLSVDKDQYVEPENVTIQCDSGYGVVGPQSITC | |||||||
Glycosylation | 506 | UniProt | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | |||||||
Disulfide bond | 511↔538 | UniProt | |||||
Sequence: CDSGYGVVGPQSITCSGNRTWYPEVPKC | |||||||
Glycosylation | 528 | UniProt | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | |||||||
Disulfide bond | 546 | UniProt | Interchain (with beta chain) | ||||
Sequence: C | |||||||
Disulfide bond | 558 | UniProt | Interchain (with beta chain) | ||||
Sequence: C |
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Chylomicrons in the plasma.
Gene expression databases
Organism-specific databases
Interaction
Subunit
Disulfide-linked complex of alpha and beta chains of 3 possible sorts: a 570 kDa complex of 7 alpha chains and 1 beta chain, a 530 kDa homoheptamer of alpha chains or a 500 kDa complex of 6 alpha chains and 1 beta chain. The central body of the alpha chain homomer supports tentacles, each with the binding site for C4b at the end.
(Microbial infection) Interacts with Staphylococcus aureus protein SdrE; this interaction inhibits complement-mediated bacterial opsonization.
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
XENO | P04003 | arp4 P13050 | 5 | EBI-978348, EBI-978341 | |
BINARY | P04003 | CRP PRO_0000023526 P02741 | 4 | EBI-978348, EBI-22033103 |
Protein-protein interaction databases
Miscellaneous
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 49-110 | Sushi 1 | ||||
Sequence: NCGPPPTLSFAAPMDITLTETRFKTGTTLKYTCLPGYVRSHSTQTLTCNSDGEWVYNTFCIY | ||||||
Domain | 111-172 | Sushi 2 | ||||
Sequence: KRCRHPGELRNGQVEIKTDLSFGSQIEFSCSEGFFLIGSTTSRCEVQDRGVGWSHPLPQCEI | ||||||
Domain | 173-236 | Sushi 3 | ||||
Sequence: VKCKPPPDIRNGRHSGEENFYAYGFSVTYSCDPRFSLLGHASISCTVENETIGVWRPSPPTCEK | ||||||
Domain | 237-296 | Sushi 4 | ||||
Sequence: ITCRKPDVSHGEMVSGFGPIYNYKDTIVFKCQKGFVLRGSSVIHCDADSKWNPSPPACEP | ||||||
Domain | 297-362 | Sushi 5 | ||||
Sequence: NSCINLPDIPHASWETYPRPTKEDVYVVGTVLRYRCHPGYKPTTDEPTTVICQKNLRWTPYQGCEA | ||||||
Domain | 363-424 | Sushi 6 | ||||
Sequence: LCCPEPKLNNGEITQHRKSRPANHCVYFYGDEISFSCHETSRFSAICQGDGTWSPRTPSCGD | ||||||
Domain | 425-482 | Sushi 7 | ||||
Sequence: ICNFPPKIAHGHYKQSSSYSFFKEEIIYECDKGYILVGQAKLSCSYSHWSAPAPQCKA | ||||||
Domain | 483-540 | Sushi 8 | ||||
Sequence: LCRKPELVNGRLSVDKDQYVEPENVTIQCDSGYGVVGPQSITCSGNRTWYPEVPKCEW |
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length597
- Mass (Da)67,033
- Last updated1993-10-01 v2
- Checksum67E03F2EA85A16DD
Computationally mapped potential isoform sequences
There are 2 potential isoforms mapped to this entry
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
M31452 EMBL· GenBank· DDBJ | AAA36507.1 EMBL· GenBank· DDBJ | mRNA | ||
M62486 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62475 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62476 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62477 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62478 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62479 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62480 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62481 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62482 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62484 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
M62485 EMBL· GenBank· DDBJ | AAA36506.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AK313164 EMBL· GenBank· DDBJ | BAG35982.1 EMBL· GenBank· DDBJ | mRNA | ||
CH471100 EMBL· GenBank· DDBJ | EAW93502.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471100 EMBL· GenBank· DDBJ | EAW93503.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC022312 EMBL· GenBank· DDBJ | AAH22312.1 EMBL· GenBank· DDBJ | mRNA | ||
X07853 EMBL· GenBank· DDBJ | CAA30701.1 EMBL· GenBank· DDBJ | mRNA | ||
X04284 EMBL· GenBank· DDBJ | CAB51244.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X04296 EMBL· GenBank· DDBJ | CAA27839.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
X02865 EMBL· GenBank· DDBJ | CAA26617.1 EMBL· GenBank· DDBJ | mRNA |