Serine palmitoyltransferase 2 (SPTLC2)
The protein contains 562 amino acids for an estimated molecular weight of 62924 Da.
Serine palmitoyltransferase (SPT). The heterodimer formed with LCB1/SPTLC1 constitutes the catalytic core. The composition of the serine palmitoyltransferase (SPT) complex determines the substrate preference. The SPTLC1-SPTLC2-SPTSSA complex shows a strong preference for C16-CoA substrate, while the SPTLC1-SPTLC2-SPTSSB complex displays a preference for C18-CoA substrate. Plays an important role in de novo sphyngolipid biosynthesis which is crucial for adipogenesis (By similarity). (updated: Feb. 13, 2019)
Protein identification was indicated in the following studies:
- 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.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
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.
This protein is predicted to be membranous by TOPCONS.
No binding partner found
Biological Process
Adipose tissue development
Ceramide biosynthetic process
Positive regulation of lipophagy
Sphinganine biosynthetic process
Sphingolipid biosynthetic process
Sphingomyelin biosynthetic process
Sphingosine biosynthetic process
The reference OMIM entry for this protein is 605713
Serine palmitoyltransferase, long-chain base subunit 2; sptlc2
Spt2
Lcb2a
Kiaa0526
DESCRIPTION
Serine palmitoyltransferase (SPT; EC 2.3.1.50) is the key enzyme in sphingolipid biosynthesis. It catalyzes the pyridoxal-5-prime-phosphate-dependent condensation of L-serine and palmitoyl-CoA to 3-oxosphinganine (Weiss and Stoffel, 1997). SPT contains 2 main subunits: the common SPTLC1 subunit (605712) and either SPTLC2 or its isoform SPTLC2L (SPTLC3; 611120), depending on the tissue in which biosynthesis occurs (Hornemann et al., 2006). There are also 2 highly related isoforms of a third subunit, SSSPTA (613540) and SSSPTB (610412), that confer acyl-CoA preference of the SPT enzyme and are essential for maximal enzyme activity (Han et al., 2009).CLONING
Weiss and Stoffel (1997) cloned and characterized 2 complete human and murine cDNA sequences which they named LCB1 (605712) and LCB2. The LCB2 cDNA encodes a protein of 562 amino acids that is more than 90% identical to the mouse protein. Northern blot analysis of mouse tissues revealed a transcript of 2.3 kb with ubiquitous expression. Nagase et al. (1998) independently cloned LCB2, which they called KIAA0526. They identified it as corresponding to the serine palmitoyltransferase subunit B of Homo sapiens. By quantitative real-time PCR analysis, Hornemann et al. (2006) detected ubiquitous SPTLC2 expression in all 24 human tissues tested. SPTLC3 (611120) and SPTLC2 showed different expression patterns, possibly reflecting tissue-specific requirements of sphingolipid synthesis. Western blot analysis detected SPTLC2 at 65 kD. Overexpression of SPTLC2 in HEK293 cells resulted in increased SPT activity by 2- to 3-fold.MAPPING
Hornemann et al. (2006) noted that the human SPTLC2 gene maps to chromosome 14q24.3. Osuka et al. (1998) mapped the murine Sptlc2 gene to chromosome 12E by FISH.MOLECULAR GENETICS
In 4 unrelated patients with hereditary sensory and autonomic neuropathy type IC (HSAN1C; 613640), Rotthier et al. (2010) identified 3 different heterozygous mutations in the SPTLC2 gene (605713.0001-605713.0003). In vitro and in vivo yeast studies indicated that the mutations resulted in partial or complete loss of enzyme activity. In addition, the 3 mutations cause the formation of the neurotoxic metabolite 1-deoxysphinganine in HEK293 cells and patient lymphoblasts. These findings were similar to those observed with SPTLC1 mutations, which cause HSAN1A (Penno et al., 2010), suggesting a common pathomechanism. ... More on the omim web site
Feb. 22, 2019: Protein entry updated
Automatic update: Entry updated from uniprot information.
Oct. 20, 2018: Protein entry updated
Automatic update: OMIM entry 605713 was added.
Oct. 19, 2018: Additional information
Initial protein addition to the database. This entry was referenced in Bryk and co-workers. (2017).