F-box/LRR-repeat protein 20 (FBXL20)

The protein contains 436 amino acids for an estimated molecular weight of 48423 Da.

 

Substrate-recognition component of the SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complex. Role in neural transmission (By similarity). (updated: March 4, 2015)

Protein identification was indicated in the following studies:

  1. Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
  2. Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
  3. Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
  4. Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
  5. D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.

Methods

The following articles were analysed to gather the proteome content of erythrocytes.

The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.

PublicationIdentification 1Uniprot mapping 2Not mapped /
Obsolete
TrEMBLSwiss-Prot
Goodman (2013)2289 (gene list)227853205992269
Lange (2014)123412347281224
Hegedus (2015)2638262202352387
Wilson (2016)165815281702911068
d'Alessandro (2017)18261817201815
Bryk (2017)20902060101081942
Chu (2018)18531804553621387

1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry

The compilation of older studies can be retrieved from the Red Blood Cell Collection database.

The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.

No sequence conservation computed yet.

Interpro domains
Total structural coverage: 0%
Model score: 0
No model available.

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The reference OMIM entry for this protein is 609086

F-box and leucine-rich repeat protein 20; fbxl20
Fbl20
Fbl2
Scrapper; scr

DESCRIPTION

Members of the F-box protein family, such as FBXL20, are characterized by an approximately 40-amino acid F-box motif. SCF complexes, formed by SKP1 (601434), cullin (see CUL1; 603134), and F-box proteins, act as protein-ubiquitin ligases. F-box proteins interact with SKP1 through the F box, and they interact with ubiquitination targets through other protein interaction domains (Jin et al., 2004).

CLONING

Jin et al. (2004) reported that the FBXL20 protein contains an N-terminal F box and 12 tandem leucine-rich repeats. By searching databases for sequences with characteristics of neuronal membrane-bound E3 ligases, Yao et al. (2007) identified human FBXL20, which they called SCRAPPER. They cloned mouse Scrapper by RT-PCR of newborn mouse brain. The deduced 438-amino acid mouse protein contains an F box, leucine-rich repeats, and a C-terminal CAAX domain for prenylation and membrane targeting. Western blot analysis of mouse tissues showed highest protein levels in brain, and expression increased with development from midgestation to adult. In situ hybridization of mouse brain detected Scrapper enriched in CA1, CA3, and dentate gyrus regions of hippocampus, as well as in cerebellum and olfactory bulb. Immunofluorescence analysis detected colocalization of Scrapper with a presynapse marker in neurons.

GENE FUNCTION

Yao et al. (2007) found that Scrapper mRNA was induced by forskolin, a cAMP signaling activator, in mouse primary hippocampal neurons. Scrapper directly bound and ubiquitinated Rim1 (RIMS1; 606629), a modulator of presynaptic plasticity, in vitro.

MAPPING

Jin et al. (2004) stated that the FBXL20 gene maps to chromosome 17q21.2 and that the mouse Fbxl20 gene maps to chromosome 11D.

ANIMAL MODEL

Yao et al. (2007) found that Scr-knockout mice died stochastically after birth and had reduced life span and smaller body size compared with wildtype littermates. Necropsy of Scr-knockout mice was unremarkable, except for a smaller pancreas. In neurons from Scr-knockout mice, Rim1 had a longer half-life, with significant reduction in ubiquitination and defective Rim1 degradation, resulting in altered electrophysiologic synaptic activity, i.e., increased frequency of miniature excitatory postsynaptic currents. The phenotype of Scr-knockout mice was phenocopied by Rim1 overexpression and could be rescued by reexpression of Scrapper or knockdown of Rim1. Proteasome inhibition resulted in upregulation of Rim1 and synaptic vesicle release probability, and these effects were blocked by impairment of Scrapper. Yao et al. (2007) concluded that SCRAPPER has an essential function in regulating the proteasome-mediated degradation of RIM1 required for synaptic tuning. ... More on the omim web site

Subscribe to this protein entry history

Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated

March 25, 2017: Additional information
No protein expression data in P. Mayeux work for FBXL20

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 609086 was added.