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Updated: Aug 8, 2026

Single-molecule Super-resolution Imaging of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane with Novel Fluorescent Probes
07:26

Single-molecule Super-resolution Imaging of Phosphatidylinositol 4,5-bisphosphate in the Plasma Membrane with Novel Fluorescent Probes

Published on: October 15, 2016

Structure of apo-phosphatidylinositol transfer protein alpha provides insight into membrane association

Arie Schouten1, Bogos Agianian, Jan Westerman

  • 1Department of Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8,NL-3584 CH Utrecht, The Netherlands.

The EMBO Journal
|May 1, 2002
PubMed

Insights

We determined the crystal structure of mouse Phosphatidylinositol transfer protein alpha (PITP alpha), revealing an open conformation. This structure suggests a mechanism for how PITP alpha binds membranes and transfers lipids for cellular processes.

Area of Science:

  • Biochemistry
  • Structural Biology
  • Cell Biology

Background:

  • Phosphatidylinositol transfer protein alpha (PITP alpha) is a conserved protein involved in phospholipid metabolism, signal transduction, and vesicular trafficking.
  • It catalyzes phospholipid exchange between membranes in vitro.
  • Its in vivo functions are crucial for cellular processes.

Purpose of the Study:

  • To determine the three-dimensional crystal structure of phospholipid-free mouse PITP alpha.
  • To elucidate the structural basis for PITP alpha's membrane association and lipid transfer mechanism.

Main Methods:

  • X-ray crystallography
  • Protein structure determination at 2.0 A resolution
  • Analysis of protein conformation and intermolecular interactions

Main Results:

  • The crystal structure revealed an open conformation of PITP alpha with a channel through the protein.
  • This open state is stabilized by hydrophobic interactions forming an intimate dimer, consistent with a membrane-bound state.
  • The structure suggests a mechanism for membrane anchoring and presentation of phosphatidylinositol.

Conclusions:

  • The open conformation of PITP alpha facilitates membrane binding and lipid transfer.
  • The findings provide insights into the molecular mechanism of PITP alpha in cellular phospholipid metabolism and signaling.
  • The structure serves as a basis for understanding PITP alpha function in vivo.

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