How Vps41 HOPS between tethering functions

How Vps41 HOPS between tethering functions

Cells find an alternative exit M ammalian cells can arrest and differentiate even in the complete absence of Rb family proteins, Wirt et al. reveal. The retinoblastoma (Rb) tumor suppressor and its close relatives p107 and p130 arrest cells in G1 by binding and inactivating E2F transcription factors, blocking transcription of E2F target genes required for cell cycle progression. The Rb family i...

Phosphorylation of a membrane curvature–sensing motif switches function of the HOPS subunit Vps41 in membrane tethering

Tethering factors are organelle-specific multisubunit protein complexes that identify, along with Rab guanosine triphosphatases, transport vesicles and trigger their SNARE-mediated fusion of specific transport vesicles with the target membranes. Little is known about how tethering factors discriminate between different trafficking pathways, which may converge at the same organelle. In this pape...

Multivalent Rab interactions determine tether-mediated membrane fusion

Membrane fusion at endomembranes requires cross-talk between Rab GTPases and tethers to drive SNARE-mediated lipid bilayer mixing. Several tethers have multiple Rab-binding sites with largely untested function. Here we dissected the lysosomal HOPS complex as a tethering complex with just two binding sites for the Rab7-like Ypt7 protein to determine their relevance for fusion. Using tethering an...

Tracking of the dynamic localization of the Rab-specific HOPS subunits reveal their distinct interaction with Ypt7 and vacuoles

Endosomal and vacuole fusion depends on the two homologous tethering complexes CORVET and HOPS. HOPS binds the activated Rab GTPase Ypt7 via two distinct subunits, Vps39 and Vps41. To understand the participation and possible polarity of Vps41 and Vps39 during tethering, we used an in vivo approach. For this, we established the ligand-induced relocalization to the plasma membrane, using the Mon...

TITLE: VPS18 recruits VPS41 to the human HOPS complex via a RING-RING interaction