Recombinant Human FCRLB/FCRY Protein, CF

Recombinant Human FCRLB/FCRY Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: FCRLB/FCRY

FCRLB, also known as FCRL2, FCRY, and FREB2, is a 60 kDa protein with sequence homology to classical Fc receptors. There are at least six type 1 transmembrane FCRL proteins and two that lack transmembrane segments. Each family member contains between three and nine immunoglobulin-like domains. FCRL proteins are differentially expressed within the B cell lineage and can either promote or inhibit B cell proliferation and activation (1, 2). According to R&D Systems testing, FCRLB binds to purified human IgG with high affinity. Human FCRLB shares 82% and 85% amino acid sequence identity with mouse and rat FCRLB, respectively. It contains a putative signal peptide, three immunoglobulin-like domains, and a mucin-like stalk that is rich in Pro, Ser, and Thr residues (1-3). The stalk region also contains di-Leu motifs and an unpaired cysteine (1-3). Alternative splicing generates isoforms with deletions in the putative signal peptide and substitutions and/or truncations in the third Ig-like domain (3). When expressed in transfectants, FCRLB is not secreted but shows a diffuse intracellular localization (3, 4). FCRLB is expressed at a low level in placenta and in B lineage cells of the germinal center (3, 4). It is up-regulated in B cells by BAFF and LPS (5). Among non-hematopoietic cells, FCRLB is expressed in fibroblasts, melanocytes, and melanoma (3, 5). It is preferentially expressed in nonproliferating cells and at the onset of apoptosis (4, 5).

Related Research Areas

• B Cell Activation
• Fc Receptors