|Chitinase domain-containing protein 1
|Ref Sequence ID
|Protein Existence Status
|positively regulates antiviral pathway.CHID1 interacts with the endocytic/sorting receptor stabilin-1 and is present in late endosomes and secretory lysosomes in alternatively activated macrophages.CHID1 overexpression enhances the activation of nuclear factor κB (NF-кB) and interferon regulatory factor 3 (IRF3) triggered by Sendai virus (SeV) by promoting the polyubiquitination of RIG-I and VISA, thereby potentiating IFN-β production.
|CHID1 is a GLYCO18 domain-containing protein that lacks catalytic amino acids and a chitin-binding domain. These have a preference for binding to chitotetraose and also to lipopolysaccharide (LPS) for neutralizing its endotoxin effect on macrophages.
|Ubl conjugation,Sumoylation, phosphorylation,acetylation,deamidation
| Site(s) of PTM(s)
|Predicted Disorder Regions
|TM Helix Prediction
|No TM helices
|Significance of PTMs
|poly ubl conjugation on K63‐ and K48 of RIG1.TRIM25 along with zinc finger protein ZCCHC3 catalyzes RIG‐I K63‐linked ubiquitination to promote RIG‐I association with MAVS and conclusively IFN‐β production.Unanchored K63‐linked ubiquitination of RIG‐I is crucial for its activation, whereas K48‐linked ubiquitination of RIG‐I or deubiquitinating of K63‐linked RIG‐I mediates the inactivation of RIG‐I.Deubiquitinating enzyme DUP17 has been reported to potentiate RIG‐I mediated antiviral signaling by associating with RIG‐I and removing polyubiquitin chains conjugated to RIG‐ I. RIG-I is dynamically sumoylated by TRIM38 in uninfected or early-infected cells to ensure their optimal activation, and then undergo desumoylation by sentrin/sumo-specific protease 2 (SENP2) and degradation at the late phase of viral infection to turn off the sustained induction of downstream antiviral genes.Sumoylation of the CARD domain of RIG-I potentiates their activation by facilitating their dephosphorylation mediated by PP1 and K63-linked polyubiquitination.
|CHID1 knockdown in human 239T cells inhibits SeV-induced activation of IRF3 and NF-κB and the induction of IFN-β.
|1.Li SN, Ling T, Yang YX, Huang JP, Xu LG. CHID1 positively regulates RLR antiviral signaling by targeting the RIG-I/VISA signalosome. J Med Virol. 2019 Sep;91(9):1668-1678. doi: 10.1002/jmv.25508. Epub 2019 Jun 25. PMID: 31106867. 2.Hu MM, Liao CY, Yang Q, Xie XQ, Shu HB. Innate immunity to RNA virus is regulated by temporal and reversible sumoylation of RIG-I and MDA5. J Exp Med. 2017 Apr 3;214(4):973-989. doi: 10.1084/jem.20161015. Epub 2017 Mar 1. PMID: 28250012; PMCID: PMC5379974.