C1QBP

Background

Complement C1q binding protein (C1QBP), also known as ASF/SF2-associated protein p32 or mitochondrial matrix protein p32, is a multifunctional and multicompartmental protein involved in many functions. It was named C1QBP since it was originally discovered as the receptor of the globular head of complement component 1q (gC1qR).

Human C1QBP is a 33 kDa highly acidic cellular protein with 282 amino acids forming three homologous subunits. It is a widely distributed multicompartmental protein that can bind to multiple ligands, such as complement C1q, kininogen-1, coagulation factor, Protein kinase D1, and so forth. C1QBP on the cell surface is thought to act as an endothelial receptor for complement C1q, which specifically binds to the globular 'heads' of C1q thus inhibiting the activation of complement C1 and complement classical pathway. Additionally, C1QBP also has been indicated to implicate in a wide variety of biological processes, including inflammation, the immune response to pathogens, ribosome biogenesis, protein synthesis in mitochondria, regulation of apoptosis, transcriptional regulation, pre-mRNA splicing, and coagulation. Recently, C1QBP has been found that over-expressed in several different types of tumor cells, and selectively bound to a tumor homing peptide LyP-1 in tumor cells.

The abnormal expression of C1QBP can cause complement dysfunctions. When involved in interactions with other ligands, C1QBP abnormity is associated with combined oxidative phosphorylation deficiency 33, Rubella, infections, and coagulation dysfunction.

Fig.1 Complement C1QBP structure.Distributed under CC BY-SA 3.0, from Wiki, without modification.

C1QBP Functional Service

Creative Biolabs provides a wide range of products specific to C1QBP, including anti-C1QBP antibodies, ELISA kits, recombinant C1QBP proteins, and reporter vectors with C1QBP clones. These precisely engineered reagents are crucial for unraveling the interactions between C1QBP proteins and diverse molecular structures, thereby propelling research endeavors aimed at crafting therapeutic strategies for a multitude of diseases.

Fig.2 Interaction between PR₅₀ protein and C1QBP: colocalization in HMC3 cell nuclei detected by immunofluorescence.¹

Amyotrophic lateral sclerosis (ALS) is a life-threatening disorder marked by the gradual degeneration of motor neurons. Researchers created a PR₅₀-expressing human HMC3 microglial cell model to further investigate. Through western blotting and immunofluorescence, C1QBP was identified as an interaction partner of PR₅₀, with its downregulation in HMC3 cells eliciting NLRP3 inflammasome activity akin to PR₅₀ expression. Additionally, researchers discovered that syringin can inhibit the PR₅₀-C1QBP interaction, effectively decreasing PR₅₀-induced NLRP3 inflammasome activity and enhancing the survival of NSC-34 cells affected by PR-CM.

Creative Biolabs provides a diverse range of functional services centered on C1QBP, including comprehensive interaction studies and various specialized analyses. These tailored services are crafted to assist researchers in advancing the boundaries of their scientific investigations and clinical pursuits.

Reference

1. Fu, Ru-Huei, et al. "C9-ALS-associated proline-arginine dipeptide repeat protein induces activation of NLRP3 inflammasome of HMC3 microglia cells by binding of complement component 1 Q subcomponent-binding protein (C1QBP), and syringin prevents this effect." Cells 11.19 (2022): 3128. Distributed under Open Access license CC BY 4.0, The image was modified by extracting and using only Part F of the original image.