Phosphoserine phosphatase (PSPH)
The protein contains 225 amino acids for an estimated molecular weight of 25008 Da.
Catalyzes the last irreversible step in the biosynthesis of L-serine from carbohydrates, the dephosphorylation of O-phospho-L-serine to L-serine (PubMed:12213811, PubMed:15291819, PubMed:9222972, PubMed:14673469, PubMed:25080166). L-serine can then be used in protein synthesis, to produce other amino acids, in nucleotide metabolism or in glutathione synthesis, or can be racemized to D-serine, a neuromodulator (PubMed:14673469). May also act on O-phospho-D-serine (Probable). (updated: June 2, 2021)
Protein identification was indicated in the following studies:
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- 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.
| 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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| Variant | Description |
|---|---|
| PSPHD | |
| PSPHD | |
| PSPHD; decreased L-phosphoserine phosphatase activity |
No binding partner found
The reference OMIM entry for this protein is 172480
Phosphoserine phosphatase; psph
Psp
DESCRIPTION
The PSPH gene encodes phosphoserine phosphatase (EC 3.1.3.3), which catalyzes the final and irreversible step of L-serine synthesis (summary by Vincent et al., 2015).CLONING
By starch gel electrophoresis, Moro-Furlani et al. (1980) detected multiple isozymes of PSP in a wide range of tissues. They suggested that rare electrophoretic variants were probably due to allelic variation at the structural locus, and that common variation existed due to secondary modification. The 3-banded isozyme pattern seen in heterozygotes (PSP2-1 and PSP3-1) suggested that PSP is dimeric. Collet et al. (1997) cloned the human PSP cDNA, which encodes a 225-amino acid polypeptide. The cDNA was expressed and yielded a 25-kD protein with the expected phosphatase activity.MAPPING
By study of somatic cell hybrids, Koch et al. (1983) assigned the structural gene for PSPH to chromosome 7 in the region pter-q22. By study of patients with structural abnormalities of 7p, Novelli and Dallapiccola (1988) refined the assignment of PSPH to 7p15.2-p15.1. The activity of PSP was increased in a patient with an unbalanced translocation associated with trisomy of the segment 7pter-p15 (Caiulo et al., 1989). Jaeken et al. (1997) noted that the assignments of the PSPH gene to 7p by Koch et al. (1983) and Novelli and Dallapiccola (1988) were based on gene dosage analysis. By genomic sequence analysis, Veiga-da-Cunha et al. (2004) found that the PSPH gene is located on 7p11.MOLECULAR GENETICS
- Phosphoserine Phosphatase Deficiency In a patient with phosphoserine phosphatase deficiency (PSPHD; 614023), who also had Williams-Bueren syndrome (WBS; 194050) and was originally reported by Jaeken et al. (1997), Veiga-da-Cunha et al. (2004) identified compound heterozygosity for 2 mutations in the PSPH gene (172480.0001; 172480.0002). They noted that the PSPH gene is separated from the elastin gene (ELN; 130160), one of several genes implicated in WBS, by 16.5 Mb. The authors concluded that there was no link between the 2 disorders in this patient. In affected members of a consanguineous Pakistani family with PSPHD, Vincent et al. (2015) identified a homozygous missense mutation in the PSPH gene (A35T; 172480.0004). The mutation, which was found by homozygosity mapping and Sanger sequencing of candidate genes, segregated with the disorder in the family. Enzymatic analysis showed that the mutant protein had approximately 10-fold lower activity than wildtype. - Associations Pending Confirmation See 172480.0003 for discussion of a possible association between variation in the PSPH gene and Neu-Laxova syndrome (see 256520). ... More on the omim web site
July 1, 2021: Protein entry updated
Automatic update: Entry updated from uniprot information.
June 30, 2020: Protein entry updated
Automatic update: OMIM entry 172480 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).