Printable factfile
Gene Information
Names
HUGO name: C1S
Alias(es):
- Complement component 1, s subcomponent
- Complement C1s component precursor (C1 esterase)
Localization
Reference sequences
- DNA: C1S_DNA (C1Sbase)
- cDNA: J04080 (EMBL)
- Protein: P09871 (SWISSPROT)
- Other Sequences
Chromosomal location
Maps
Variations / Mutations
Other gene-based resources
Protein Information
Description
Protein function:
C1s b chain is a serine protease that combines with C1q and C1s to form C1, the first component of the classical pathway of the complement system. C1r activates C1s so that it can, in turn, activate C2 and C4.
Catalytic activity:
Cleaves component C4 to C4a and C4b, and component C2 to C2a and C2b.
Subunit:
C1 is a calcium-dependent trimolecular complex of C1q, r and s in the molar ration of 1:2:2. Activated C1s is an disulfide-linked heterodimer of an heavy chain and a light chain.
Structures (PDB)
Domains
Cub 1 domain: 16-130
Egf-like, calcium-binding domain: 131-172
Cub 2 domain: 175-290
Sushi 1 domain: 293-355
Sushi 2 domain: 358-422
Serine protease domain: 438-688
Other features
Signal peptide: 1-15
Complement c1s heavy chain: 16-437
Complement c1s light chain: 438-688
Other related resourses:
- PIR: C1HUS
- InterPro: IPR000152; Asx_hydroxyl
- InterPro: IPR000859; CUB_domain
- InterPro: IPR001314; Chymotrypsin
- InterPro: IPR006210; EGF-like
- InterPro: IPR001881; EGF_Ca
- InterPro: IPR001254; Ser_protease_Try
- InterPro: IPR000436; Sushi_SCR_CCP
- Pfam: PF00008; EGF
- Pfam: PF00084; sushi
- Pfam: PF00089; trypsin
- Pfam: PF00431; CUB
- SMART: SM00032; CCP
- SMART: SM00042; CUB
- SMART: SM00179; EGF_CA
- SMART: SM00020; Tryp_SPc
- PROSITE: PS00010; ASX_HYDROXYL
- PROSITE: PS01180; CUB
- PROSITE: PS00022; EGF_1
- PROSITE: PS01186; EGF_2
- PROSITE: PS01187; EGF_CA
- PROSITE: PS50240; TRYPSIN_DOM
- PROSITE: PS00134; TRYPSIN_HIS
- PROSITE: PS00135; TRYPSIN_SER
Expression
Expression pattern for human
| Tissue | Expression (%) | Clones |
|---|---|---|
| connective tissue | 9.43 | 3:1301 |
| thyroid gland | 7.20 | 2:1136 |
| nasopharynx | 6.33 | 1:646 |
| subchondral bone | 6.14 | 2:1332 |
| brain, meningioma | 5.77 | 1:709 |
| adipose | 4.82 | 1:849 |
| pancreas, exocrine | 4.39 | 23:21418 |
| mammary gland | 2.84 | 1:1441 |
| esophagus | 2.77 | 2:2949 |
| lung with fibrosis | 2.77 | 1:1479 |