Overview
| Uniprot ID | P07358 |
|---|
| Protein Name | Complement component C8 beta chain |
|---|
| Gene Name | C8B |
|---|
| Organism | Homo sapiens |
|---|
Kla Sites from experimental identification
| Position |
Flanking peptide |
| 411 |
RGILNEIKDRNKRDT |
| 415 |
NEIKDRNKRDTMVED |
Function
Component of the membrane attack complex (MAC), a multiprotein complex activated by the complement cascade, which inserts into a target cell membrane and forms a pore, leading to target cell membrane rupture and cell lysis (PubMed:22832194, PubMed:26841837, PubMed:27052168, PubMed:30552328, PubMed:7440581). The MAC is initiated by proteolytic cleavage of C5 into complement C5b in response to the classical, alternative, lectin and GZMK complement pathways (PubMed:30552328, PubMed:39914456, PubMed:39814882, PubMed:7440581). The complement pathways consist in a cascade of proteins that leads to phagocytosis and breakdown of pathogens and signaling that strengthens the adaptive immune system (PubMed:30552328, PubMed:7440581). C8B, together with C8A and C8G, inserts into the target membrane, but does not form pores by itself (PubMed:30552328). During MAC assembly, associates with C5b, C6 and C7 to form the C5b8 intermediate complex that inserts into the target membrane and traverses the bilayer increasing membrane rigidity (PubMed:30552328, PubMed:6833260)
Protein Sequence
10
MKNSRTWAWR
20
APVELFLLCA
30
ALGCLSLPGS
40
RGERPHSFGS
50
NAVNKSFAKS
60
RQMRSVDVTL
70
MPIDCELSSW
80
SSWTTCDPCQ
90
KKRYRYAYLL
100
QPSQFHGEPC
110
NFSDKEVEDC
120
VTNRPCGSQV
130
RCEGFVCAQT
140
GRCVNRRLLC
150
NGDNDCGDQS
160
DEANCRRIYK
170
KCQHEMDQYW
180
GIGSLASGIN
190
LFTNSFEGPV
200
LDHRYYAGGC
210
SPHYILNTRF
220
RKPYNVESYT
230
PQTQGKYEFI
240
LKEYESYSDF
250
ERNVTEKMAS
260
KSGFSFGFKI
270
PGIFELGISS
280
QSDRGKHYIR
290
RTKRFSHTKS
300
VFLHARSDLE
310
VAHYKLKPRS
320
LMLHYEFLQR
330
VKRLPLEYSY
340
GEYRDLFRDF
350
GTHYITEAVL
360
GGIYEYTLVM
370
NKEAMERGDY
380
TLNNVHACAK
390
NDFKIGGAIE
400
EVYVSLGVSV
410
GKCRGILNEI
420
KDRNKRDTMV
430
EDLVVLVRGG
440
ASEHITTLAY
450
QELPTADLMQ
460
EWGDAVQYNP
470
AIIKVKVEPL
480
YELVTATDFA
490
YSSTVRQNMK
500
QALEEFQKEV
510
SSCHCAPCQG
520
NGVPVLKGSR
530
CDCICPVGSQ
540
GLACEVSYRK
550
NTPIDGKWNC
560
WSNWSSCSGR
570
RKTRQRQCNN
580
PPPQNGGSPC
590
SGPASETLDC
S
Gene Ontology
| Classification |
GO ID |
Description |
| Cellular Component |
GO:0070062 |
extracellular exosome |
| Cellular Component |
GO:0005576 |
extracellular region |
| Cellular Component |
GO:0005615 |
extracellular space |
| Cellular Component |
GO:1903561 |
extracellular vesicle |
| Cellular Component |
GO:0016020 |
membrane |
| Cellular Component |
GO:0005579 |
membrane attack complex |
| Cellular Component |
GO:0044218 |
other organism cell membrane |
| Cellular Component |
GO:0005886 |
plasma membrane |
| Molecular Function |
GO:0044877 |
protein-containing complex binding |
| Biological Process |
GO:0006956 |
complement activation |
| Biological Process |
GO:0006957 |
complement activation, alternative pathway |
| Biological Process |
GO:0006958 |
complement activation, classical pathway |
| Biological Process |
GO:0160257 |
complement activation, GZMK pathway |
| Biological Process |
GO:0006955 |
immune response |
| Biological Process |
GO:0031640 |
killing of cells of another organism |
| Biological Process |
GO:0050778 |
positive regulation of immune response |
| Biological Process |
GO:0055085 |
transmembrane transport |
Reference
[1] Shi CM, Wang QC, Li XL, Yang YH, Tang XY et al.. Global Profiling of Protein Lactylation in Human Hippocampi.. Proteomics Clin Appl 19(2):e202400061. 2025 Mar. PMID: 39610256.