F-box only protein 44

Function

Substrate-recognition component of two distinct E3 ligase complexes, the SKP1-CUL1-FBXO44 complex and the CUL4B-DDB1-FBXO44 complex. The complex SCF(FBXO44) complex ubiquitinates and mediates BRCA1 degradation. In association with cullin 4B/CUL4B and DDB1, mediates the ubiquitination of RGS2 leading to its degradation. Additionally, regulates the pregnane X receptor/NR1I2 protein level by ubiquitination and degradation.

Classification

Family (Pfam)

PF12937 F-box-like, PF04300 FBA

InterPro

F-box-assoc_dom, F-box-like_dom_sf, F-box_dom, F-box_only, Galactose-bd-like_sf

Functional cluster

Mixed Regulatory & Membrane Proteins

Experimental structures · PDB · 2

• 3WSO X-ray 2.60A
• 5B4N X-ray 2.30A

A predicted model is available from AlphaFold.

Gene Ontology · 10

• GO:0005737 cytoplasm
• GO:0005829 cytosol
• GO:0005634 nucleus
• GO:0019005 SCF ubiquitin ligase complex
• GO:1990756 ubiquitin-like ligase-substrate adaptor activity
• GO:0036503 ERAD pathway
• GO:0006516 glycoprotein catabolic process
• GO:0010498 proteasomal protein catabolic process
• GO:0043161 proteasome-mediated ubiquitin-dependent protein catabolic process
• GO:0031146 SCF-dependent proteasomal ubiquitin-dependent protein catabolic process

Neighborhood · nearest proteins

Related proteins · sequence + function similarity

• F-box only protein 44 0.99
• F-box only protein 6 0.87
• F-box only protein 6 0.82
• F-box only protein 6 0.75
• F-box only protein 6 0.69
• Protein-L-histidine N-pros-methyltransferase 0.59
• Protein-L-histidine N-pros-methyltransferase 0.59
• Protein GUCD1 0.59
• Protein-L-histidine N-pros-methyltransferase 0.58
• Protein-L-histidine N-pros-methyltransferase 0.58
• Protein GUCD1 0.57
• Queuosine-tRNA galactosyltransferase 0.57

Co-cited proteins · studied together in the literature

• Nuclear receptor subfamily 1 group I member 2 1 shared papers
• F-box only protein 6 1 shared papers
• F-box only protein 27 2 shared papers
• F-box only protein 17 2 shared papers
• Regulator of G protein signaling 2 1 shared papers
• Breast cancer type 1 susceptibility protein 1 shared papers
• F-box only protein 27 1 shared papers
• F-box only protein 44 1 shared papers
• F-box only protein 17 1 shared papers
• Cullin-4B 1 shared papers
• F-box only protein 6 1 shared papers
• F-box only protein 6 1 shared papers

Literature · 9 cited papers

• The F-box-only protein 44 regulates pregnane X receptor protein level by ubiquitination and degradation. Acta Pharm. Sin. B (APSB) · 2023
• FBXO44-Mediated Degradation of RGS2 Protein Uniquely Depends on a Cullin 4B/DDB1 Complex. PLoS ONE · 2015
• The F-box protein FBXO44 mediates BRCA1 ubiquitination and degradation. J. Biol. Chem. · 2012
• Diversity in tissue expression, substrate binding, and SCF complex formation for a lectin family of ubiquitin ligases. J. Biol. Chem. · 2008
• The full-ORF clone resource of the German cDNA consortium. BMC Genomics · 2007
• The DNA sequence and biological annotation of human chromosome 1. Nature · 2006
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome Res. · 2004
• Complete sequencing and characterization of 21,243 full-length human cDNAs. Nat. Genet. · 2004
• A new subfamily of structurally related human F-box proteins. Gene · 2002