Description: Homo sapiens inositol-3-phosphate synthase 1 (ISYNA1), transcript variant 1, mRNA. RefSeq Summary (NM_016368): This gene encodes an inositol-3-phosphate synthase enzyme. The encoded protein plays a critical role in the myo-inositol biosynthesis pathway by catalyzing the rate-limiting conversion of glucose 6-phosphate to myoinositol 1-phosphate. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene, and a pseudogene of this gene is located on the short arm of chromosome 4. [provided by RefSeq, Nov 2011]. Transcript (Including UTRs) Position: hg19 chr19:18,545,198-18,548,570 Size: 3,373 Total Exon Count: 7 Strand: - Coding Region Position: hg19 chr19:18,545,723-18,547,652 Size: 1,930 Coding Exon Count: 6
ID:INO1_HUMAN DESCRIPTION: RecName: Full=Inositol-3-phosphate synthase 1; Short=IPS 1; EC=5.5.1.4; AltName: Full=Myo-inositol 1-phosphate synthase; Short=MI-1-P synthase; Short=MIP synthase; Short=hIPS; AltName: Full=Myo-inositol 1-phosphate synthase A1; Short=hINO1; FUNCTION: Key enzyme in myo-inositol biosynthesis pathway that catalyzes the conversion of glucose 6-phosphate to 1-myo-inositol 1-phosphate in a NAD-dependent manner. Rate-limiting enzyme in the synthesis of all inositol-containing compounds. CATALYTIC ACTIVITY: D-glucose 6-phosphate = 1D-myo-inositol 3- phosphate. COFACTOR: NAD. ENZYME REGULATION: Inhibited by mood-stabilizing drugs such as valproate (VPA) and lithium. BIOPHYSICOCHEMICAL PROPERTIES: Kinetic parameters: KM=0.57 mM for 6-phosphate; KM=8 uM for NAD; pH dependence: Optimum pH is 8.0; PATHWAY: Polyol metabolism; myo-inositol biosynthesis; myo- inositol from D-glucose 6-phosphate: step 1/2. SUBCELLULAR LOCATION: Cytoplasm (By similarity). TISSUE SPECIFICITY: Highly expressed in testis, ovary, heart, placenta and pancreas. Weakly expressed in blood leukocyte, thymus, skeletal muscle and colon. INDUCTION: By glucose and lovastain. Up-regulation is prevented by mevalonic acid, farnesol, and geranylgeraniol. Up-regulated by E2F1. SIMILARITY: Belongs to the myo-inositol 1-phosphate synthase family. SEQUENCE CAUTION: Sequence=AAP97151.1; Type=Frameshift; Positions=82, 85, 496;
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on Q9NPH2
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
Biological Process: GO:0006021 inositol biosynthetic process GO:0006629 lipid metabolic process GO:0008654 phospholipid biosynthetic process GO:0043647 inositol phosphate metabolic process