en Complement factor B

CFB
Available structures
PDB	Ortholog search: PDBe RCSB
List of PDB id codes
	3HS0, 1DLE, 1Q0P, 1RRK, 1RS0, 1RTK, 2OK5, 2WIN, 2XWB, 2XWJ, 3HRZ
Identifiers
Aliases	CFB, Cfb, AI195813, AI255840, Bf, C2, Fb, H2-Bf, AHUS4, ARMD14, BFD, CFAB, CFBD, FBI12, GBG, PBF2, complement factor B
External IDs	OMIM: 138470; MGI: 105975; HomoloGene: 1292; GeneCards: CFB; OMA:CFB - orthologs
Gene location (Human)
Chr.	Chromosome 6 (human)
End	31,952,084 bp
Gene location (Mouse)
Chr.	Chromosome 17 (mouse)
End	35,081,494 bp
RNA expression pattern
	Top expressed in
	right lobe of liver; ; gallbladder; ; appendix; ; duodenum; ; islet of Langerhans; ; olfactory zone of nasal mucosa; ; Descending thoracic aorta; ; gastric mucosa; ; right coronary artery; ; human kidney;
	Top expressed in
	proximal tubule; ; right kidney; ; human kidney; ; white adipose tissue; ; hepatobiliary system; ; liver; ; jejunum; ; ileum; ; colon; ; duodenum;
	More reference expression data
	; ;
	More reference expression data
Gene ontology
Molecular function	peptidase activity; serine-type peptidase activity; serine-type endopeptidase activity; hydrolase activity; complement binding; protein binding;
Cellular component	extracellular region; plasma membrane; blood microparticle; extracellular exosome; extracellular space;
Biological process	complement activation; regulation of complement activation; proteolysis; immune system process; complement activation, alternative pathway; innate immune response;
	Sources:Amigo / QuickGO
Orthologs
	629
	14962
ENSG00000243570; ENSG00000239754; ENSG00000243649; ENSG00000241253; ENSG00000242335;
	ENSG00000241534; ENSG00000204359
	ENSMUSG00000090231
	P00751
	P04186
	NM_001710
	NM_001142706; NM_008198
	NP_001701
	NP_001136178; NP_032224; NP_001389804
	Wikidata
View/Edit Human	View/Edit Mouse

Complement factor B is a protein that in humans is encoded by the CFB gene.^[5]

Function

This gene encodes complement factor B, a component of the alternative pathway of complement activation. Factor B circulates in the blood as a single chain polypeptide. Upon activation of the alternative pathway, it is cleaved by complement factor D yielding the noncatalytic chain Ba and the catalytic subunit Bb. The active subunit Bb is a serine protease that associates with C3b to form the alternative pathway C3 convertase. Bb is involved in the proliferation of preactivated B lymphocytes, while Ba inhibits their proliferation. This gene localizes to the major histocompatibility complex (MHC class III) region on chromosome 6. This cluster includes several genes involved in regulation of the immune reaction. The polyadenylation site of this gene is 421 bp from the 5' end of the gene for complement component 2.^[5]

Complement tests
C4 (C)	FB (A)	C3	CH50	Conditions
·	↓	↓	↓	PSG, C3 NeF AA
↓	·	↓	·	HAE, C4D
·	·	·	↓	TCPD
↓	·/↓	↓	↓	SLE
↑	↑	↑	↑	inflammation

References

^ ^a ^b ^c ENSG00000239754, ENSG00000243649, ENSG00000241253, ENSG00000242335, ENSG00000241534, ENSG00000204359 GRCh38: Ensembl release 89: ENSG00000243570, ENSG00000239754, ENSG00000243649, ENSG00000241253, ENSG00000242335, ENSG00000241534, ENSG00000204359 – Ensembl, May 2017
^ ^a ^b ^c GRCm38: Ensembl release 89: ENSMUSG00000090231 – Ensembl, May 2017
^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ ^a ^b "Entrez Gene: CFB complement factor B".

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Woods DE, Markham AF, Ricker AT, Goldberger G, Colten HR (September 1982). "Isolation of cDNA clones for the human complement protein factor B, a class III major histocompatibility complex gene product". Proceedings of the National Academy of Sciences of the United States of America. 79 (18): 5661–5. Bibcode:1982PNAS...79.5661W. doi:10.1073/pnas.79.18.5661. PMC 346964. PMID 6957884.
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