Using innovative approaches such as phospholipid-specific antibodies and reconstituted cell-free systems, Jean Gruenberg and his colleagues were able to unravel several important mechanisms regulating the biogenesis and membrane dynamics of early and late endosomal compartments.

[citation needed] Jean Gruenberg and his family reside in Trelex Switzerland and he works at the University of Geneva as an emeritus professor in the Department of Biochemistry.

After early studies on parasites (T. brucei and P. falciparum),[1][2] Jean Gruenberg switched focus and studied the dynamics endosomal processes when he started to work at the European Molecular Biology Laboratory (EMBL) with Kate Howell, and made several important discoveries on the molecular factors directing endosome dynamics, and was successful in reconstituting the process in vitro.

Using the Vesicular Stomatitis Virus (VSV) as a “hijacker” of the endocytic pathway, Jean Gruenberg and his colleagues demonstrated that intralumenal vesicles present within multivesicular endosomes are able to undergo back-fusion with the limiting membrane of these organelles, thus releasing their content into the cytoplasm,[41] a process regulated by the ESCRT-related proteins TSG101[39] and ALIX,[42] and since shown to be exploited by various other invaders of the cells such as the Anthrax toxin,[43] and several other viruses.

[44] A milestone discovery in the career of Jean Gruenberg was the identification and the characterization of an atypical inverted cone-shaped phospholipid,[45] originally named lysobisphosphatidic acid (LBPA) and also known as bis(monoacylglycero)phosphate (BMP).