title: Optogenetic acidification of synaptic vesicles and lysosomes.
abstract: Acidification is required for the function of many intracellular organelles, but methods to acutely manipulate their intraluminal pH have not been available. Here we present a targeting strategy to selectively express the light-driven proton pump Arch3 on synaptic vesicles. Our new tool, pHoenix, can functionally replace endogenous proton pumps, enabling optogenetic control of vesicular acidification and neurotransmitter accumulation. Under physiological conditions, glutamatergic vesicles are nearly full, as additional vesicle acidification with pHoenix only slightly increased the quantal size. By contrast, we found that incompletely filled vesicles exhibited a lower release probability than full vesicles, suggesting preferential exocytosis of vesicles with high transmitter content. Our subcellular targeting approach can be transferred to other organelles, as demonstrated for a pHoenix variant that allows light-activated acidification of lysosomes.
authors.affiliation: Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.|German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Rost
authors.affiliation: Institute of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany.|Current address: National Heart and Lung Institute, Imperial College London, United Kingdom.
authors.forename: Franziska
authors.initials: F
authors.lastname: Schneider
authors.affiliation: Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: M Katharina
authors.initials: MK
authors.lastname: Grauel
authors.affiliation: Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.|University of Strathclyde, Glasgow, UK.
authors.forename: Christian
authors.initials: C
authors.lastname: Wozny
authors.affiliation: Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Bentz
authors.affiliation: Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.|Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Blessing
authors.affiliation: Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Rosenmund
authors.affiliation: Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.|Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Jentsch
authors.affiliation: Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Schmitz
authors.affiliation: Institute of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hegemann
authors.affiliation: Neuroscience Research Center, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Rosenmund
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005260:Female; D057809:HEK293 Cells; D006624:Hippocampus / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008247:Lysosomes / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D062308:Optogenetics / Q000379:methods*; D051381:Rats; D013572:Synaptic Vesicles / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism