72 kD inositol polyphosphate 5-phosphatase; phosphatidylinositol polyphosphate 5-phosphatase type 4; phosphatidylinositol-4,5-bisphosphate 5-phosphatase (INPP5E)

Function

• converts phosphatidylinositol-3,4,5-triphosphate (Ptdins-3,4,5-P3) to Ptdins-P2
• specific for lipid substrates, inactive towards water soluble inositol phosphates
• phosphorylated upon DNA damage, probably by ATM or ATR

Inhibition:

• completely inhibited by CTAB
• active in the presence of octyl-glucoside or triton X-100

Structure

• belongs to the inositol-1,4,5-trisphosphate 5-phosphatase type IV family

Compartment

• cytoplasm, cytoskeleton, cilium axoneme
• Golgi, Golgi stack membrane
• peripheral membrane, cytoplasmic side (putative)

Alternative splicing

named isoforms=2

Expression

• detected in brain, heart, pancreas, testis & spleen

Pathology

• defects in INPP5E are the cause of
  • Joubert syndrome type 1
  • mental retardation-truncal obesity-retinal dystrophy-micropenis

More general terms

• phosphomonoesterase

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=56623
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:56623
• OMIM: https://mirror.omim.org/entry/213300
• OMIM: https://mirror.omim.org/entry/610156
• OMIM: https://mirror.omim.org/entry/613037
• UniProt: http://www.uniprot.org/uniprot/Q9NRR6.html