Trafficking of phosphatidylinositol by phosphatidylinositol transfer proteins.

  title={Trafficking of phosphatidylinositol by phosphatidylinositol transfer proteins.},
  author={Shamshad Cockcroft},
  journal={Biochemical Society symposium},
  • S. Cockcroft
  • Published 12 January 2007
  • Biology, Chemistry
  • Biochemical Society symposium
PtdIns is synthesized at the endoplasmic reticulum and its intracellular distribution to other organelles can be facilitated by lipid transfer proteins [PITPs (phosphatidylinositol transfer proteins)]. In this review, I summarize the current understanding of how PITPs are regulated by phosphorylation, how can they dock to membranes to exchange their lipid cargo and how cells use PITPs in signal transduction and membrane delivery. Mammalian PITPs, PITPalpha and PITPbeta, are paralogous genes… 

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The diverse functions of phosphatidylinositol transfer proteins.

  • S. Cockcroft
  • Biology
    Current topics in microbiology and immunology
  • 2012
It is proposed that PITPs are regulators of phosphoinositide pathways by recruitment to membranes through specific protein interactions to promote molecular exchange between closely opposed membranes i.e., at membrane contact sites.

Biochemical and biological functions of class I phosphatidylinositol transfer proteins.

Dynamics of Lipid Transfer by Phosphatidylinositol Transfer Proteins in Cells

To study PITP dynamics in intact cells, chemically targeted their C95 residue that, although non‐essential for lipid transfer, is buried within the phospholipid‐binding cavity, and so, its chemical modification prevents PtdIns binding because of steric hindrance.

Function of the phosphatidylinositol transfer protein gene family: is phosphatidylinositol transfer the mechanism of action?

The common mechanism underlying each of these phenotypes is identified as the cooperation between PITP proteins and lipid kinases through the provision of PI for phosphorylation.

Phosphatidylinositol- and phosphatidylcholine-transfer activity of PITPβ is essential for COPI-mediated retrograde transport from the Golgi to the endoplasmic reticulum

It is demonstrated that the PtdIns and PtdCho exchange activity of PITPβ is essential for COPI-mediated retrograde transport from the Golgi to the ER.

The phosphatidylinositol transfer protein RdgBβ binds 14-3-3 via its unstructured C-terminus, whereas its lipid-binding domain interacts with the integral membrane protein ATRAP (angiotensin II type I receptor-associated protein).

It is suggested that RdgBβ executes its function following recruitment to membranes via its PITP domain and the C-terminal end of the protein could regulate entry to the hydrophobic cavity.

Molecular insights into conformational dynamics associated with the open-closed-phosphorylated states of PITPα

The study shows that the open state is highly dynamic and its transition to closed state would stabilize PITP α, and the impact of phosphorylation on the global conformation of PITPα is discussed.

The multiple roles of PtdIns(4)P – not just the precursor of PtdIns(4,5)P2

The aim of this Commentary is to describe the present knowledge of PtdIns(4)P metabolism and the molecular machineries that are directly regulated by Ptd insurance within and outside of the Golgi complex.


Genes to cells