C1RB

Background

C1rb (complement component 1, r subcomponent B), also known as Gm8551 or mC1rB. is a vital serine protease. It has been reported that in mice, the C1r gene duplicates to produce two isoforms, C1ra and C1rb, with vastly different tissue distributions. For example, C1ra is primarily found in the small intestine, liver, blood, and midbrain, while C1rB is found in male reproductive organs, including the prostate and coagulation glands.

Its Gene ID: 667277 and UniProtKB ID: Q8CFG9.

Structural Characteristics

Similar to C1ra, C1rb also contains multiple specific domains. However, there are differences between the primary sequences of C1ra and C1rb, and this difference is mainly found in the SP domain. In addition, the scientists found that the aa sequence identity between the mouse full-length C1ra and C1rB is 96%. Mouse C1rB has 79.9% identity with human C1r. Notably, the modular structure of C1rb is the same as that of the human protein. Notably, there are differences in the distribution of amino acid residues between humans and mice, and this is prevalent in the SP domain.

Main Functions of C1rb

C1rb combines with C1q and C1s to form C1, which serves as the first component of the classical pathway of the complement system. Specifically, activation of C1 promotes the conversion of C1r proenzyme to C1r enzyme. This signal helps activate two C1s proenzymes. C1s then combine with C4 to produce C4a and C4b, which in turn facilitates the splitting of C2 into C2a and C2b. Subsequently, C3 convertase cleaves C3 into C3a and C3b, and C3b can combine with the C4b2a combination to produce C5 convertase. Subsequently, C5 is catalyzed by C5 convertase to form C5a and C5b. C5b is associated with other complementary components to create a complex that mediates the lysis of invasive bacteria.

Fig.1 C1r and classical complement pathways.¹

What Can We Offer?

With decades of experience in complement research, Creative Biolabs is fully committed to providing you with first-class C1rb-related products to safeguard your complement projects.

• Assay Kits

Mouse Complement C1RB ELISA Kit

• Proteins

Recombinant Mouse Complement Component C1rb Protein

• Vectors

Mouse Complement C1rb (NM_001113356) Myc-DDK tagged ORF clone-CTDNA-023

For quotes and details on C1rb-related products, contact our complement team.

Reference

1. Batista, André F., et al. "The importance of complement-mediated immune signaling in Alzheimer’s disease pathogenesis." International Journal of Molecular Sciences 25.2 (2024): 817.