F-Box/LRR-Repeat Protein 2 (FBXL2) Human Recombinant Protein

This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbls class and, in addition to an F-box, contains 12 tandem leucine-rich repeats. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jan 2010]

FBXL2: Calcium-activated substrate recognition component of a SCF (SKP1-cullin-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Unlike many F-box proteins, FBXL2 doesn't seem to target phosphodegron within its substrates but rather calmodulin-binding motifs. Targets PCYT1A for its monoubiquitination and degradation, this is antagonized by calmodulin. Targets the cyclins CCND2 and CCND3 for polyubiquitination and degradation, leading to cell-cycle arrest in G(0), also antagonized by calmodulin. Binds to hepatitis C virus non-structural protein 5A (NS5A) in a reaction crucial for hepatitis C virus RNA replication.

Protein type: Ubiquitin ligase

Chromosomal Location of Human Ortholog: 3p22.3

Cellular Component: cytoplasm; membrane; SCF ubiquitin ligase complex

Molecular Function: calmodulin binding; protein binding; protein phosphatase binding; ubiquitin-protein ligase activity

Biological Process: protein modification process; protein monoubiquitination; protein ubiquitination; proteolysis; regulation of autophagy; regulation of phosphoinositide 3-kinase cascade; SCF-dependent proteasomal ubiquitin-dependent protein catabolic process; viral reproduction