72 kDa inositol polyphosphate 5-phosphatase, also known as phosphatidylinositol-4,5-bisphosphate 5-phosphatase or Pharbin, is an enzyme that in humans is encoded by the INPP5E gene.^[1]^[2]

Function

INPP5E is a phosphatidylinositol (3,4,5)-trisphosphate (PtdInsP3) and phosphatidylinositol 4,5-bisphosphate 5-phosphatase. Its intracellular localization is the primary cilium, a small organelle involved in signal transduction. INPP5E plays a role in hydrolyzing PtdInsP3 produced in response to various growth factors such as PDGF. Inactivation of the mouse INPP5E gene decreases primary cilia stability, leading to a multiorgan disorder, including absence of eyes, polydactyly, exencephaly and renal cysts.

Clinical significance

Mutations in the INPP5E are associated with MORM syndrome^[3] and Joubert syndrome.^[4]

References

Jin J, Smith FD, Stark C, Wells CD, Fawcett JP, Kulkarni S, Metalnikov P, O'Donnell P, Taylor P, Taylor L, Zougman A, Woodgett JR, Langeberg LK, Scott JD, Pawson T (August 2004). "Proteomic, functional, and domain-based analysis of in vivo 14-3-3 binding proteins involved in cytoskeletal regulation and cellular organization". Current Biology. 14 (16): 1436–50. doi:10.1016/j.cub.2004.07.051. PMID 15324660. S2CID 2371325.
Kong AM, Speed CJ, O'Malley CJ, Layton MJ, Meehan T, Loveland KL, Cheema S, Ooms LM, Mitchell CA (August 2000). "Cloning and characterization of a 72-kDa inositol-polyphosphate 5-phosphatase localized to the Golgi network". The Journal of Biological Chemistry. 275 (31): 24052–64. doi:10.1074/jbc.M000874200. PMID 10806194.
Jacoby M, Cox JJ, Gayral S, Hampshire DJ, Ayub M, Blockmans M, Pernot E, Kisseleva MV, Compère P, Schiffmann SN, Gergely F, Riley JH, Pérez-Morga D, Woods CG, Schurmans S (September 2009). "INPP5E mutations cause primary cilium signaling defects, ciliary instability and ciliopathies in human and mouse" (PDF). Nature Genetics. 41 (9): 1027–31. doi:10.1038/ng.427. PMID 19668215. S2CID 5249668.
Ono A, Ablan SD, Lockett SJ, Nagashima K, Freed EO (October 2004). "Phosphatidylinositol (4,5) bisphosphate regulates HIV-1 Gag targeting to the plasma membrane". Proceedings of the National Academy of Sciences of the United States of America. 101 (41): 14889–94. Bibcode:2004PNAS..10114889O. doi:10.1073/pnas.0405596101. PMC 522033. PMID 15465916.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

v t e Ciliary proteins
Nephrocystin	NPHP1 INVS NPHP3 NPHP4 IQCB1 CEP290 GLIS2 RPGRIP1L
Basal body	BBsome BBS1 BBS2 BBS4 BBS5 BBS7 TTC8 BBS9 chaperone MKKS BBS10 BBS12 Other ARL6 TRIM32 ALMS1 CC2D2A CEP290 MKS1 RPGRIP1L OFD1 AHI1 INVS NPHP4 NEK8 NPHP1
Cilia	connecting cilia LCA5 RP1 RPGR RPGRIP1 TULP1 primary cilia ARL13B INPP5E IQCB1 PKHD1 PKD1 PKD2 TMEM67
Dynein	outer dynein arms DNAH5 DNAI2 DNAL1 axoneme DNAH11 DNAI1
Radial spokes	RSPH1 RSPH3 RSPH4A RSPH6A RSPH9 RSPH10B
Other	cytoplasm KTU nucleus GLIS2 intraflagellar transport IFT80 other AHI1 ARL13B BRCC3 INPP5E KIF3A LRRC50 SDCCAG8 TMEM216 TXNDC3
see also: ciliopathy

Hydrolase: esterases (EC 3.1)

3.1.1: Carboxylic
ester hydrolases

Lipase

Phospholipase
- A1
- A2
- B

3.1.2: Thioesterase

3.1.3: Phosphatase

3.1.4:
Phosphodiesterase

3.1.6: Sulfatase

Nuclease (includes
deoxyribonuclease
and ribonuclease)

3.1.11-16:
Exonuclease

Exodeoxyribonuclease	RecBCD
Exoribonuclease	Oligonucleotidase

3.1.21-31:
Endonuclease

Endodeoxyribonuclease	Deoxyribonuclease I Deoxyribonuclease II Deoxyribonuclease IV Restriction enzyme;see ((Restriction enzyme)) UvrABC endonuclease
Endoribonuclease	RNase III Drosha: Microprocessor complex Dicer: RNA-induced silencing complex RNase H 1 2A 2B 2C RNase P RNase A RNase Z RNase E 1 2 3 4/5 RNase T1
either deoxy- or ribo-	Nuclease S1 Mung bean nuclease Serratia marcescens nuclease Micrococcal nuclease

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)

Function

Clinical significance

References

Further reading