Gene/Proteome Database (LMPD)
LMPD ID
LMP001881
Gene ID
Species
Homo sapiens (Human)
Gene Name
sphingomyelin synthase 2
Gene Symbol
Synonyms
SMS2
Chromosome
4
Map Location
4q25
EC Number
2.7.8.27
Summary
Sphingomyelin, a major component of cell and Golgi membranes, is made by the transfer of phosphocholine from phosphatidylcholine onto ceramide, with diacylglycerol as a side product. The protein encoded by this gene is an enzyme that catalyzes this reaction primarily at the cell membrane. The synthesis is reversible, and this enzyme can catalyze the reaction in either direction. The encoded protein is required for cell growth. Three transcript variants encoding the same protein have been found for this gene. There is evidence for more variants, but the full-length nature of their transcripts has not been determined.[provided by RefSeq, Oct 2008]
Orthologs
Proteins
| phosphatidylcholine:ceramide cholinephosphotransferase 2 | |
|---|---|
| Refseq ID | NP_001129729 |
| Protein GI | 210147407 |
| UniProt ID | Q8NHU3 |
| mRNA ID | NM_001136257 |
| Length | 365 |
| RefSeq Status | REVIEWED |
| MDIIETAKLEEHLENQPSDPTNTYARPAEPVEEENKNGNGKPKSLSSGLRKGTKKYPDYIQIAMPTESRNKFPLEWWKTGIAFIYAVFNLVLTTVMITVVHERVPPKELSPPLPDKFFDYIDRVKWAFSVSEINGIILVGLWITQWLFLRYKSIVGRRFCFIIGTLYLYRCITMYVTTLPVPGMHFQCAPKLNGDSQAKVQRILRLISGGGLSITGSHILCGDFLFSGHTVTLTLTYLFIKEYSPRHFWWYHLICWLLSAAGIICILVAHEHYTIDVIIAYYITTRLFWWYHSMANEKNLKVSSQTNFLSRAWWFPIFYFFEKNVQGSIPCCFSWPLSWPPGCFKSSCKKYSRVQKIGEDNEKST | |
| phosphatidylcholine:ceramide cholinephosphotransferase 2 | |
|---|---|
| Refseq ID | NP_689834 |
| Protein GI | 22749271 |
| UniProt ID | Q8NHU3 |
| mRNA ID | NM_152621 |
| Length | 365 |
| RefSeq Status | REVIEWED |
| Protein sequence is identical to GI:210147407 (mRNA isoform) | |
| phosphatidylcholine:ceramide cholinephosphotransferase 2 | |
|---|---|
| Refseq ID | NP_001129730 |
| Protein GI | 210147409 |
| UniProt ID | Q8NHU3 |
| mRNA ID | NM_001136258 |
| Length | 365 |
| RefSeq Status | REVIEWED |
| Protein sequence is identical to GI:210147407 (mRNA isoform) | |
Gene Information
Gene Ontology (GO Annotations)
| GO ID | Source | Type | Description |
|---|---|---|---|
| GO:0005794 | IDA:MGI | C | Golgi apparatus |
| GO:0030173 | IDA:UniProtKB | C | integral component of Golgi membrane |
| GO:0045203 | IEA:Ensembl | C | integral component of cell outer membrane |
| GO:0005887 | IDA:UniProtKB | C | integral component of plasma membrane |
| GO:0005886 | TAS:Reactome | C | plasma membrane |
| GO:0047493 | IDA:UniProtKB | F | ceramide cholinephosphotransferase activity |
| GO:0016301 | IEA:UniProtKB-KW | F | kinase activity |
| GO:0033188 | IEA:UniProtKB-EC | F | sphingomyelin synthase activity |
| GO:0044281 | TAS:Reactome | P | small molecule metabolic process |
| GO:0030148 | TAS:Reactome | P | sphingolipid biosynthetic process |
| GO:0006665 | TAS:Reactome | P | sphingolipid metabolic process |
| GO:0006686 | IDA:UniProtKB | P | sphingomyelin biosynthetic process |
KEGG Pathway Links
| KEGG Pathway ID | Description |
|---|---|
| hsa00600 | Sphingolipid metabolism |
BIOCYC Pathway Links
| BIOCYC Pathway ID | Description |
|---|---|
| PWY3DJ-11281 | sphingomyelin metabolism |
REACTOME Pathway Links
| REACTOME Pathway ID | Description |
|---|---|
| REACT_115810 | Sphingolipid de novo biosynthesis |
Domain Information
InterPro Annotations
| Accession | Description |
|---|---|
| IPR025749 | Sphingomyelin synthase-like domain |
UniProt Annotations
Entry Information
Comments
| Comment Type | Description |
|---|---|
| Catalytic Activity | A ceramide + a phosphatidylcholine = a sphingomyelin + a 1,2-diacyl-sn-glycerol. |
| Enzyme Regulation | Inhibited by bacterial PC-phospholipase C inhibitor D609. |
| Function | Sphingomyelin synthases synthesize the sphingolipid, sphingomyelin, through transfer of the phosphatidyl head group, phosphatidylcholine, on to the primary hydroxyl of ceramide. The reaction is bidirectional depending on the respective levels of the sphingolipid and ceramide. Plasma membrane SMS2 can also convert phosphatidylethanolamine (PE) to ceramide phosphatidylethanolamine (CPE). Major form in liver. Required for cell growth in certain cell types. Regulator of cell surface levels of ceramide, an important mediator of signal transduction and apoptosis. Regulation of sphingomyelin (SM) levels at the cell surface affects insulin sensitivity. {ECO |
| Miscellaneous | Overexpression of the human protein in mouse causes increased non-HDL-sphingomyelin and non-HDL cholesterol levels, decreased HDL-sphingomyelin and HDL-cholesterol levels and increases lipoprotein atherogenic potential. |
| Ptm | Palmitoylated on Cys-331, Cys-332, Cys-343 and Cys-348; which plays an important role in plasma membrane localization. |
| Similarity | Belongs to the sphingomyelin synthase family. |
| Subcellular Location | Cell membrane; Multi-pass membrane protein. Golgi apparatus membrane; Multi-pass membrane protein. Note=Predominantly plasma membrane, some in Golgi apparatus. Some localization in the perinuclear region where it colocalizes with a sialyltransferase. |
| Tissue Specificity | Brain, heart, kidney, liver, muscle and stomach. Also expressed in a number of cell lines such as carcinoma HeLa cells, hepatoma Hep-G2 cells, and colon carcinoma Caco-2 cells. |
Identical and Related Proteins
Unique RefSeq proteins for LMP001881 (as displayed in Record Overview)
| Protein GI | Database | Accession | Length | Protein Name |
|---|---|---|---|---|
| 210147407 | RefSeq | NP_001129729 | 365 | phosphatidylcholine:ceramide cholinephosphotransferase 2 |
Identical Sequences to LMP001881 proteins
| Reference | Database | Accession | Length | Protein Name |
|---|---|---|---|---|
| GI:210147407 | GenBank | JAA18899.1 | 365 | sphingomyelin synthase 2 [Pan troglodytes] |
| GI:210147407 | GenBank | JAA18900.1 | 365 | sphingomyelin synthase 2 [Pan troglodytes] |
| GI:210147407 | GenBank | JAA27411.1 | 365 | sphingomyelin synthase 2 [Pan troglodytes] |
| GI:210147407 | GenBank | JAA39885.1 | 365 | sphingomyelin synthase 2 [Pan troglodytes] |
| GI:210147407 | GenBank | AIC53326.1 | 365 | SGMS2, partial [synthetic construct] |
| GI:210147407 | RefSeq | XP_006714184.1 | 365 | PREDICTED: phosphatidylcholine:ceramide cholinephosphotransferase 2 isoform X1 [Homo sapiens] |
Related Sequences to LMP001881 proteins
| Reference | Database | Accession | Length | Protein Name |
|---|---|---|---|---|
| GI:210147407 | RefSeq | XP_003830042.1 | 365 | PREDICTED: phosphatidylcholine:ceramide cholinephosphotransferase 2 [Pan paniscus] |
| GI:210147407 | RefSeq | XP_004040296.1 | 365 | PREDICTED: phosphatidylcholine:ceramide cholinephosphotransferase 2 isoform 1 [Gorilla gorilla gorilla] |
| GI:210147407 | RefSeq | XP_004040297.1 | 365 | PREDICTED: phosphatidylcholine:ceramide cholinephosphotransferase 2 isoform 2 [Gorilla gorilla gorilla] |
| GI:210147407 | RefSeq | XP_007997669.1 | 365 | PREDICTED: phosphatidylcholine:ceramide cholinephosphotransferase 2 [Chlorocebus sabaeus] |
| GI:210147407 | RefSeq | XP_007997670.1 | 365 | PREDICTED: phosphatidylcholine:ceramide cholinephosphotransferase 2 [Chlorocebus sabaeus] |
| GI:210147407 | RefSeq | XP_010371510.1 | 365 | PREDICTED: phosphatidylcholine:ceramide cholinephosphotransferase 2 [Rhinopithecus roxellana] |