Functional patchworking at the plasma membrane

Abstract

Lipids and proteins are not evenly distributed within the plasma membrane (PM), but instead segregate laterally into many specialized microdomains whose functional relevance is not clear. In this issue, Busto et al (2018) demonstrate that substrate flux through a nutrient transporter drives the lateral relocation of the transporter between specific microdomains at the yeast PM, suggesting that regulating the lateral plasma membrane compartmentalization for individual proteins could be a general process for cellular response to environmental conditions.

Figure 1. The cartoon represents the functional patchworking at the plasma membrane for the methionine transporter Mup1

(1) Mup1 is sequestered in the MCC in its open outward conformation and protected from ubiquitination and endocytosis. The lateral diffusion (arrows) out of the MCC and into the network‐like domain is slow. (2) Upon transport of substrate (methionine) through Mup1, the change to the open inward conformation drives the efficient relocation from the MCC into the network‐like domain. (3) In the network‐like domain, Mup1 is ubiquitinated by Art1/Rsp5 (not shown) which results in the recruitment of the endocytic machinery, actin, and subsequent endocytosis.