phosphatidylinositol-3,4-bisphosphate 3-phosphatase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: 1-phosphatidyl-1D-myo-inositol 3,4-bisphosphate + H2O = 1-phosphatidyl-1D-myo-inositol 4-phosphate + phosphate. [GOC:bf, PMID:9811831]

Phosphatidylinositol-3,4-bisphosphate 3-phosphatase activity is a catalytic activity that removes a phosphate group from the 3-position of phosphatidylinositol-3,4-bisphosphate (PIP3), converting it to phosphatidylinositol-4-phosphate (PIP2). This reaction is crucial for regulating various cellular processes, including:

1. **Signal transduction:** PIP3 is a key second messenger involved in signaling pathways downstream of receptor tyrosine kinases and G protein-coupled receptors. By dephosphorylating PIP3, phosphatidylinositol-3,4-bisphosphate 3-phosphatases (PTEN and SHIP) terminate PIP3-mediated signaling, effectively acting as "off-switches" for these pathways.

2. **Cell growth and proliferation:** PIP3 is essential for cell growth and proliferation. PTEN, a major phosphatidylinositol-3,4-bisphosphate 3-phosphatase, acts as a tumor suppressor by inhibiting PIP3 accumulation and thus suppressing uncontrolled cell growth.

3. **Cell migration and adhesion:** PIP3 plays a role in regulating cell migration and adhesion by controlling the formation of focal adhesions. PTEN can modulate these processes by regulating PIP3 levels.

4. **Membrane trafficking:** PIP3 is involved in regulating membrane trafficking events, including endocytosis and exocytosis. Phosphatidylinositol-3,4-bisphosphate 3-phosphatases can affect these processes by modulating PIP3 levels at specific membrane locations.

5. **Insulin signaling:** PIP3 is a key player in insulin signaling, mediating downstream effects on glucose uptake and metabolism. PTEN, by regulating PIP3 levels, plays a role in insulin sensitivity.

The molecular function of phosphatidylinositol-3,4-bisphosphate 3-phosphatase activity is thus tightly linked to numerous cellular functions, highlighting its importance in maintaining cellular homeostasis and signaling.'
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Proteins (2)

Compounds (1)