Phosphatidylinositol polyphosphate 5-phosphatase type IV
Function
Phosphatidylinositol (PtdIns) phosphatase that specifically hydrolyzes the 5-phosphate of phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P3), phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) and phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2) (By similarity) (PubMed:10764818). Specific for lipid substrates, inactive towards water soluble inositol phosphates (PubMed:10764818). Plays an essential role in the primary cilium by controlling ciliary growth and phosphoinositide 3-kinase (PI3K) signaling and stability (By similarity).
Involvement in disease
Joubert syndrome 1
JBTS1
A disorder presenting with cerebellar ataxia, oculomotor apraxia, hypotonia, neonatal breathing abnormalities and psychomotor delay. Neuroradiologically, it is characterized by cerebellar vermian hypoplasia/aplasia, thickened and reoriented superior cerebellar peduncles, and an abnormally large interpeduncular fossa, giving the appearance of a molar tooth on transaxial slices (molar tooth sign). Additional variable features include retinal dystrophy and renal disease.
None
The disease is caused by variants affecting the gene represented in this entry.
Impaired intellectual development, truncal obesity, retinal dystrophy, and micropenis
MORMS
An autosomal recessive disorder characterized by moderate intellectual disability, truncal obesity, congenital non-progressive retinal dystrophy, and micropenis in males. The phenotype is similar to Bardet-Biedl syndrome and Cohen syndrome Distinguishing features are the age of onset, the non-progressive nature of the visual impairment, lack of dysmorphic facies, skin or gingival infection, microcephaly, mottled retina, polydactyly, and testicular anomalies.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the inositol 1,4,5-trisphosphate 5-phosphatase type IV family.
Tissue Specificity
Detected in brain, heart, pancreas, testis and spleen.
Cellular localization
- Cytoplasm
- Cytoskeleton
- Cilium axoneme
- Golgi apparatus
- Golgi stack membrane
- Peripheral membrane protein
- Cytoplasmic side
- Cell membrane
- Peripheral membrane protein
- Cytoplasmic side
- Cell projection
- Ruffle
- Cytoplasm
- Nucleus
- Peripheral membrane protein associated with Golgi stacks.
Alternative names
Phosphatidylinositol polyphosphate 5-phosphatase type IV, 72 kDa inositol polyphosphate 5-phosphatase, Inositol polyphosphate-5-phosphatase E, INPP5E