Bro1 directly stimulates Vps4 activity to promote Intralumenal Vesicle Formation during Multivesicular Body biogenesis

Katzmann, D.; Tseng, C.-c.; Dean, S.; Davies, B. A.; Azmi, I. F.; Pashkova, N.; Payne, J. A.; Staffenhagen, J.; West, M.; Piper, R. C.; Odorizzi, G.

doi:10.1101/2020.07.27.223255

bioRxiv · 10.1101/2020.07.27.223255

Bro1 directly stimulates Vps4 activity to promote Intralumenal Vesicle Formation during Multivesicular Body biogenesis

Katzmann, D.·Tseng, C.-c.·Dean, S.·Davies, B. A.·Azmi, I. F.·Pashkova, N.·Payne, J. A.·Staffenhagen, J.·West, M.·Piper, R. C.·Odorizzi, G.

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Abstract

Endosomal sorting complexes required for transport (ESCRT-0, -I, -II, -III) execute cargo sorting and intralumenal vesicle (ILV) formation during conversion of endosomes to multivesicular bodies (MVBs). The AAA-ATPase Vps4 regulates the ESCRT-III polymer to facilitate membrane remodeling and ILV scission during MVB biogenesis. Here we show that the conserved V domain of ESCRT-associated protein Bro1 (the yeast homolog of mammalian proteins ALIX and HD-PTP) directly stimulates Vps4. This activity is required for MVB cargo sorting. Furthermore, the Bro1 V domain alone supports Vps4/ESCRT-driven ILV formation in vivo without efficient MVB cargo sorting. These results reveal a novel activity of the V domains of Bro1 homologs in licensing ESCRT-III-dependent ILV formation and suggest a role in coordinating cargo sorting with membrane remodeling during MVB sorting. Moreover, ubiquitin binding enhances V domain stimulation of Vps4 to promote ILV formation via the Bro1/Vps4/ESCRT-III axis, uncovering a novel role for ubiquitin during MVB biogenesis in addition to facilitating cargo recognition. SummaryCargo sorting is coordinated with intralumenal vesicle budding during ESCRT-mediated multivesicular body biogenesis. Bro1 V domain stimulates Vps4 to promote ESCRT-III-driven intralumenal vesicle formation in a manner required for this coordinated process.

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Katzmann, D., Tseng, C.-c., Dean, S., Davies, B. A., Azmi, I. F., Pashkova, N., Payne, J. A., Staffenhagen, J., West, M., Piper, R. C., Odorizzi, G.. 2020-07-28. Bro1 directly stimulates Vps4 activity to promote Intralumenal Vesicle Formation during Multivesicular Body biogenesis. https://doi.org/10.1101/2020.07.27.223255

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