A noncanonical function of SKP1 regulates the switch between autophagy and unconventional secretion

Intracellular degradation of proteins and organelles by the autophagy-lysosome system is essential for cellular quality control and energy homeostasis. Besides degradation, endolysosomal organelles can fuse with the plasma membrane and contribute to unconventional secretion. Here, we identify a function for mammalian SKP1 in endolysosomes that is independent of its established role as an essential component of the family of SCF/CRL1 ubiquitin ligases. We found that, under nutrient-poor conditions, SKP1 is phosphorylated on Thr131, allowing its interaction with V1 subunits of the vacuolar ATPase (V-ATPase). This event, in turn, promotes V-ATPase assembly to acidify late endosomes and enhance endolysosomal degradation. Under nutrient-rich conditions, SUMOylation of phosphorylated SKP1 allows its binding to and dephosphorylation by the PPM1B phosphatase. Dephosphorylated SKP1 interacts with SEC22B to promote unconventional secretion of the content of less acidified hybrid endosomal/autophagic compartments. Collectively, our study implicates SKP1 phosphorylation as a switch between autophagy and unconventional secretion in a manner dependent on cellular nutrient status.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:9

Enthalten in:

Science advances - 9(2023), 41 vom: 13. Okt., Seite eadh1134

Sprache:

Englisch

Beteiligte Personen:

Li, Jie [VerfasserIn]
Krause, Gregory J [VerfasserIn]
Gui, Qi [VerfasserIn]
Kaushik, Susmita [VerfasserIn]
Rona, Gergely [VerfasserIn]
Zhang, Qingyue [VerfasserIn]
Liang, Feng-Xia [VerfasserIn]
Dhabaria, Avantika [VerfasserIn]
Anerillas, Carlos [VerfasserIn]
Martindale, Jennifer L [VerfasserIn]
Vasilyev, Nikita [VerfasserIn]
Askenazi, Manor [VerfasserIn]
Ueberheide, Beatrix [VerfasserIn]
Nudler, Evgeny [VerfasserIn]
Gorospe, Myriam [VerfasserIn]
Cuervo, Ana Maria [VerfasserIn]
Pagano, Michele [VerfasserIn]

Links:

Volltext

Themen:

EC 3.6.1.-
Journal Article
Vacuolar Proton-Translocating ATPases

Anmerkungen:

Date Completed 07.11.2023

Date Revised 02.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1126/sciadv.adh1134

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM363247432