The intramembrane proteases SPPL2a and SPPL2b regulate the homeostasis of selected SNARE proteins

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

Abstract

Signal peptide peptidase (SPP) and SPP-like (SPPL) aspartyl intramembrane proteases are known to contribute to sequential processing of type II-oriented membrane proteins referred to as regulated intramembrane proteolysis. The ER-resident family members SPP and SPPL2c were shown to also cleave tail-anchored proteins, including selected SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins facilitating membrane fusion events. Here, we analysed whether the related SPPL2a and SPPL2b proteases, which localise to the endocytic or late secretory pathway, are also able to process SNARE proteins. Therefore, we screened 18 SNARE proteins for cleavage by SPPL2a and SPPL2b based on cellular co-expression assays, of which the proteins VAMP1, VAMP2, VAMP3 and VAMP4 were processed by SPPL2a/b demonstrating the capability of these two proteases to proteolyse tail-anchored proteins. Cleavage of the four SNARE proteins was scrutinised at the endogenous level upon SPPL2a/b inhibition in different cell lines as well as by analysing VAMP1-4 levels in tissues and primary cells of SPPL2a/b double-deficient (dKO) mice. Loss of SPPL2a/b activity resulted in an accumulation of VAMP1-4 in a cell type- and tissue-dependent manner, identifying these proteins as SPPL2a/b substrates validated in vivo. Therefore, we propose that SPPL2a/b control cellular levels of VAMP1-4 by initiating the degradation of these proteins, which might impact cellular trafficking.

Details

OriginalspracheEnglisch
Seiten (von - bis)2320-2337
Seitenumfang18
FachzeitschriftThe FEBS journal
Jahrgang290 (2023)
Ausgabenummer9
PublikationsstatusVeröffentlicht - 3 Mai 2023
Peer-Review-StatusJa

Externe IDs

Scopus 85137931704
WOS 000853432900001
Mendeley fe894a11-6a88-3706-a3ec-5f428f70bf79

Schlagworte

Schlagwörter

  • Intramembrane proteolysis, Membrane trafficking, Protein degradation, SNARE protein, Signal peptide peptidase-like proteases, intramembrane proteolysis, membrane trafficking, protein degradation, signal peptide peptidase-like proteases