1. Regulation of lysosomal positioning via TMEM55B phosphorylation
- Author
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Makoto Araki and Kenji Kontani
- Subjects
MAPK/ERK pathway ,MAP Kinase Signaling System ,Dynein ,Vesicular Transport Proteins ,macromolecular substances ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Microtubule ,Dynein ATPase ,Animals ,Humans ,Phosphorylation ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,Chemistry ,Autophagy ,General Medicine ,Transmembrane protein ,Cell biology ,Kinesin ,Phosphoinositide Phosphatases ,Lysosomes ,030217 neurology & neurosurgery - Abstract
Lysosomes are dynamic organelles that are transported along microtubules bidirectionally via kinesin and dynein motor proteins. Lysosomal positioning, which is determined by the balance of the bidirectional lysosomal movement, changes under various conditions and affects lysosomal functions such as autophagy and antigen presentation. A recent study by Takemasu et al. (Phosphorylation of TMEM55B by Erk/MAPK regulates lysosomal positioning. J. Biochem. 2019; 166:175โ185) has shown that phosphorylation of the transmembrane protein TMEM55B is involved in the retrograde lysosomal trafficking towards the perinuclear region. They found that TMEM55B is phosphorylated upon stimulation with various ligands and that Erk/MAPK mediates the TMEM55B phosphorylation. They have also revealed that a phosphorylation mimic mutant of TMEM55B enhances perinuclear lysosomal clustering compared to the wild-type TMEM55B. These findings suggest that TMEM55B phosphorylation by Erk/MAPK is responsible for regulating lysosomal positioning in response to external stimuli.
- Published
- 2021