# Microautophagy: current understanding of its molecular mechanisms and functions

## TL;DR

This paper reviews what is known about microautophagy, a process where cells break down materials using specialized membrane structures.

## Contribution

The paper provides a comprehensive overview of recent advances in understanding the molecular mechanisms of microautophagy.

## Key findings

- Microautophagy involves invagination or protrusion of endolysosomal membranes.
- The molecular mechanisms of microautophagy remain largely unknown compared to macroautophagy.
- The paper summarizes current knowledge of microautophagy across different eukaryotic cells.

## Abstract

Microautophagy (MI-autophagy) is an umbrella term for intracellular degradative pathways that entail the invagination or protrusion of the limiting membranes of endolysosomal compartments, that is, late endosomes and mammalian lysosomes or yeast and plant vacuoles, followed by pinching-off of the membrane into the lumen of the organelle. During these processes, the material specifically and nonspecifically targeted for degradation is sequestered within the invaginating or protuberating membrane. In contrast to macroautophagy, the molecular mechanisms underlying MI-autophagy are largely unknown due to their diversity and complexity in location, regulation and molecular machinery requirements. Here, we review recent progress in the field of MI-autophagy, describing the molecular basis and functions of the MI-autophagic pathways reported to date in eukaryotic cells, from yeast to mammalian and plant cells.