PI(4,5)P2 is dephosphorylated to PI4P by SYNJ/INPP5[1] at the plasma membrane

Stable Identifier
Reaction [transition]
Homo sapiens
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At the plasma membrane, Synaptojanin-1 (SYNJ1) and -2 (SYNJ2), inositol polyphosphate 5-phosphatase K (INPP5K) aka SKIP, phosphatidylinositol 4,5-bisphosphate 5-phosphatase A (INPP5J) aka PIPP dephosphorylate phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) to form phosphatidylinositol 4-phosphate (PI4P). SYNJ1/2 both have an N-terminal Sac1-like domain, a central 5-phosphatase domain and a C-terminal proline-rich segment, with this latter part being the most divergent part of the protein sequence.

The following lists the above proteins with their corresponding literature references: SYNJ1 (Johenning et al. 2004, Haffner et al. 1997, Guo et al. 1999, Mani et al. 2007), SYNJ2 (Malecz et al. 2000), INPP5K (Injuin et al. 2000, Gurung et al. 2003), and INPP5J (Gurung et al. 2003, Mochizuki & Takenawa 1999).

Literature References
PubMed ID Title Journal Year
12536145 Identification of a novel domain in two mammalian inositol-polyphosphate 5-phosphatases that mediates membrane ruffle localization. The inositol 5-phosphatase skip localizes to the endoplasmic reticulum and translocates to membrane ruffles following epidermal growth factor stimulation

Tan, A, Prescott, M, Munday, AD, Mitchell, CA, McGrath, MJ, Gurung, R, Whisstock, JC, Huysmans, RD, Ooms, LM

J Biol Chem 2003
11084340 Synaptojanin 2, a novel Rac1 effector that regulates clathrin-mediated endocytosis

Qiu, R, McCabe, PC, Malecz, N, Spaargaren, C, Chuang, Y, Symons, M

Curr Biol 2000
10753883 Identification and characterization of a novel inositol polyphosphate 5-phosphatase

Funaki, M, Ijuin, T, Fukami, K, Takenawa, T, Asano, T, Mochizuki, Y

J Biol Chem 2000
15080793 InsP3-mediated intracellular calcium signalling is altered by expression of synaptojanin-1

Lee, E, Ehrlich, BE, Uhlén, P, Johenning, FW, Degray, B, Wenk, MR, De Camilli, P

Biochem J 2004
18093523 The dual phosphatase activity of synaptojanin1 is required for both efficient synaptic vesicle endocytosis and reavailability at nerve terminals

Ryan, TA, Cremona, O, Di Paolo, G, Mani, M, Lucast, L, De Camilli, P, Lee, SY

Neuron 2007
10224048 SAC1-like domains of yeast SAC1, INP52, and INP53 and of human synaptojanin encode polyphosphoinositide phosphatases

Lemrow, SM, Guo, S, Stolz, LE, York, JD

J Biol Chem 1999
9428629 Synaptojanin 1: localization on coated endocytic intermediates in nerve terminals and interaction of its 170 kDa isoform with Eps15

Di Fiore, PP, Salcini, AE, Hudson, A, Haffner, C, Chen, H, Butler, MH, Ringstad, N, Takei, K, De Camilli, P

FEBS Lett 1997
10593988 Novel inositol polyphosphate 5-phosphatase localizes at membrane ruffles

Takenawa, T, Mochizuki, Y

J Biol Chem 1999
Catalyst Activity

phosphatidylinositol-4,5-bisphosphate 5-phosphatase activity of SYNJ/INPP5(1) [cytosol]

Orthologous Events
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