Names & Taxonomy

Uniprot ID:
P02745
Entry Name:
C1QA_HUMAN
Status:
reviewed
Protein Names:
Complement C1q subcomponent subunit A
Gene Names:
C1QA
Gene Names Primary:
C1QA
Organism:
Homo sapiens (Human)

Structure

Length:
245
Sequence:
MEGPRGWLVLCVLAISLASMVTEDLCRAPDGKKGEAGRPGRRGRPGLKGEQGEPGAPGIRTGIQGLKGDQGEPGPSGNPGKVGYPGPSGPLGARGIPGIKGTKGSPGNIKDQPRPAFSAIRRNPPMGGNVVIFDTVITNQEEPYQNHSGRFVCTVPGYYYFTFQVLSQWEICLSIVSSSRGQVRRSLGFCDTTNKGLFQVVSGGMVLQLQQGDQVWVEKDPKKGHIYQGSEADSVFSGFLIFPSA
Proteomes:
UP000005640

Subcellular location

Subcellular Location:
Secreted.

Function

Function:
C1q associates with the proenzymes C1r and C1s to yield C1, the first component of the serum complement system. The collagen-like regions of C1q interact with the Ca(2+)-dependent C1r(2)C1s(2) proenzyme complex, and efficient activation of C1 takes place on interaction of the globular heads of C1q with the Fc regions of IgG or IgM antibody present in immune complexes.
Cross Reference Drug Bank:
DB00054 DB00051 DB00092 DB00087 DB00074 DB00112 DB00002 DB00111 DB00095 DB00005 DB00056 DB00078 DB00075 DB00108 DB00110 DB00073 DB00081 DB00072
Gene Ontology Go:
collagen trimer
complement component C1 complex
extracellular exosome
extracellular region
cell-cell signaling
complement activation
complement activation, classical pathway
innate immune response
response to iron ion
Gene Ontology Biological Process:
cell-cell signaling
complement activation
complement activation, classical pathway
innate immune response
response to iron ion
Gene Ontology Cellular Component:
collagen trimer
complement component C1 complex
extracellular exosome
extracellular region
Keywords:
3D-structure
Collagen
Complement pathway
Complete proteome
Direct protein sequencing
Disulfide bond
Glycoprotein
Hydroxylation
Immunity
Innate immunity
Polymorphism
Reference proteome
Repeat
Secreted
Signal
Interacts With:
P02746

Publication

PubMed ID:
1706597 14702039 16710414 15489334 486087 6981411 16335952 19159218 12960167 9777412