Glycosaminoglycan xylosylkinase (FAM20B)
The protein contains 409 amino acids for an estimated molecular weight of 46432 Da.
Responsible for the 2-O-phosphorylation of xylose in the glycosaminoglycan-protein linkage region of proteoglycans thereby regulating the amount of mature GAG chains. Sulfated glycosaminoglycans (GAGs), including heparan sulfate and chondroitin sulfate, are synthesized on the so-called common GAG-protein linkage region (GlcUAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser) of core proteins, which is formed by the stepwise addition of monosaccharide residues by the respective specific glycosyltransferases. Xylose 2-O-phosphorylation may influence the catalytic activity of B3GAT3 (GlcAT-I) which completes the precursor tetrasaccharide of GAG-protein linkage regions on which the repeating disaccharide region is synthesized. (updated: Oct. 10, 2018)
Protein identification was indicated in the following studies:
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.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
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.
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No binding partner found
The reference OMIM entry for this protein is 611063
Family with sequence similarity 20, member b; fam20b
Kiaa0475
CLONING
By sequencing clones obtained from a size-fractionated human brain cDNA library, Seki et al. (1997) obtained a partial FAM20B clone, which they designated KIAA0475. The 3-prime UTR contains 2 Alu sequences. By database analysis with the mouse Fam20a (611062) sequence as query, Nalbant et al. (2005) identified a family of genes with related sequence that included 2 additional members in mammals, FAM20B and FAM20C (611061). The 3 deduced proteins are highly conserved in human, mouse, and rat. All contain a conserved putative signal sequence and a conserved C-terminal sequence. The deduced human FAM20B protein contains 459 amino acids. Expression analysis showed that, like FAM20A, FAM20B and FAM20C are expressed during hematopoiesis.MAPPING
By radiation hybrid analysis, Seki et al. (1997) mapped the FAM20B gene to chromosome 1. Hartz (2014) mapped the FAM20B gene to chromosome 1q25.2 based on an alignment of the FAM20B sequence (GenBank GENBANK AB007944) with the genomic sequence (GRCh37).ANIMAL MODEL
Vogel et al. (2012) found that deletion of the Fam20b gene in mice resulted in embryonic lethality. At 12.5 days postcoitus, Fam20b -/- embryos showed severely stunted growth, with multisystem organ hypoplasia and delayed development most evident in skeletal system, eye, lung, gastrointestinal tract, and liver. ... More on the omim web site
Oct. 19, 2018: Protein entry updated
Automatic update: OMIM entry 611063 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).