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Updated: Dec 16, 2025

Reconstitution of Msp1 Extraction Activity with Fully Purified Components
Published on: August 10, 2021
TMEM16K is an interorganelle regulator of endosomal sorting
Maja Petkovic1, Juan Oses-Prieto2, Alma Burlingame2
1Departments of Physiology, Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, 94158, USA. Maja.Petkovic@ucsf.edu.
Abstract:
Communication between organelles is essential for their cellular homeostasis. Neurodegeneration reflects the declining ability of neurons to maintain cellular homeostasis over a lifetime, where the endolysosomal pathway plays a prominent role by regulating protein and lipid sorting and degradation. Here we report that TMEM16K, an endoplasmic reticulum lipid scramblase causative for spinocerebellar ataxia (SCAR10), is an interorganelle regulator of the endolysosomal pathway. We identify endosomal transport as a major functional cluster of TMEM16K in proximity biotinylation proteomics analyses. TMEM16K forms contact sites with endosomes, reconstituting split-GFP with the small GTPase RAB7. Our study further implicates TMEM16K lipid scrambling activity in endosomal sorting at these sites. Loss of TMEM16K function led to impaired endosomal retrograde transport and neuromuscular function, one of the symptoms of SCAR10. Thus, TMEM16K-containing ER-endosome contact sites represent clinically relevant platforms for regulating endosomal sorting.
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