Atg9b

Transcription factor EB (TFEB) is a member of the MiTF/TFE (Microphthalmia/TFE) subfamily of basic/helix-loop-helix/leucine zipper transcription factors. This group of proteins is involved in the proliferation and development of specific cell types such as osteoclasts or melanocytes. Recently scientists have begun to uncover the roles of MiTF/TFE proteins in organelle biogenesis and energy metabolism (1). TFEB, for example, is a known regulator of lysosome biogenesis.

Atg9 is the only essential transmembrane protein involved in cellular autophagy. Autophagy regulates cellular homeostasis by allowing the turnover and recycling of misfolded proteins and damaged organelles. Formation of the double-membrane isolation membrane that forms the pre-autophagosome requires the contribution of highly mobile cytoplasmic vesicles containing Atg9. These vesicles are derived from recycling endosomes and are responsible for recruiting and delivering lipid components to the assembling autophagosome.