Chapter 16 - Non-vesicular lipid transport at membrane contact sites between the endoplasmic reticulum and the plasma membrane

Abstract

Membrane contact sites (MCSs) are zones where cellular membranes are closely apposed. In most cases, the endoplasmic reticulum (ER), which is widely distributed throughout the cells, forms MCSs with other cellular membranes including the plasma membrane (PM). MCSs, including those at the PM, have been demonstrated to be the sites of non-vesicular lipid transport mediated by the so-called lipid transfer proteins (LTPs). LTPs harbor lipids in their hydrophobic cavity and transfer them between the juxtaposed membranes at the MCSs. Several LTPs that function at the ER-PM MCSs have been identified, and their lipid transfer function directly controls the distribution and metabolism of lipids as well as tightly coupled with other cellular processes including signaling, Ca2+ dynamics and membrane trafficking. The ER-PM MCS can be considered as a platform that couples lipid transfer with other cellular processes.