Spermidine synthase (SRM)
The protein contains 302 amino acids for an estimated molecular weight of 33825 Da.
Catalyzes the production of spermidine from putrescine and decarboxylated S-adenosylmethionine (dcSAM). Has a strong preference for putrescine as substrate, and has very low activity towards 1,3-diaminopropane. Has extremely low activity towards spermidine. (updated: April 1, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- 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.
- 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.
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 |
|---|---|
| dbSNP:rs1049932 |
The reference OMIM entry for this protein is 182891
Spermidine synthase; srm
Sps1
CLONING
The biosynthesis of polyamines, which are universally essential for cellular functions, takes place from arginine and methionine and involves 4 distinct enzymes: spermidine synthase (EC 2.5.1.16), ornithine decarboxylase (165640), S-adenosyl-L-methionine decarboxylase (180980), and spermine synthase (300105). Wahlfors et al. (1990) cloned a cDNA coding for the full-length subunit of spermidine synthase, using a synthetic deoxyoligonucleotide mixture corresponding to a tryptic peptide of the bovine enzyme and a human decidual cDNA library. An open reading frame for a 302-amino acid polypeptide was found.GENE STRUCTURE
Myohanen et al. (1991) isolated the SRM gene from a genomic library and showed that it comprises 5,818 nucleotides from the cap site to the last A of the putative polyadenylation signal with 8 exons.MAPPING
Using Southern blot analysis of panels of human/rodent somatic cell hybrids and chromosomal in situ hybridization, Winqvist et al. (1991) assigned spermidine synthase DNA sequences to 1p36-p22 and 3p14-q21. As determined from the intensity of the hybridization signal observed in analysis of DNA from somatic cell hybrids, it seemed likely that the functional gene is located at the former site. By PCR analysis of DNA obtained from human/hamster somatic cell hybrids, Myohanen et al. (1991) mapped the SRM gene to chromosome 1. ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 182891 was added.
Jan. 28, 2016: Protein entry updated
Automatic update: model status changed
Jan. 25, 2016: Protein entry updated
Automatic update: model status changed