Université de Fribourg

Multilayered control of protein turnover by torc1 and atg1

Hu, Zehan ; Raucci, Serena ; Jaquenoud, Malika ; Hatakeyama, Riko ; Stumpe, Michael ; Rohr, Rudolf ; Reggiori, Fulvio ; Virgilio, Claudio De ; Dengjel, Jörn

In: Cell Reports, 2019, vol. 28, no. 13, p. 3486-3496.e6

The target of rapamycin complex 1 (TORC1) is a master regulator of cell homeostasis, which promotes anabolic reactions and synchronously inhibits catabolic processes such as autophagy-mediated protein degradation. Its prime autophagy target is Atg13, a subunit of the Atg1 kinase complex that acts as the gatekeeper of canonical autophagy. To study whether the activities of TORC1 and Atg1 are...

Université de Fribourg

The I-BAR protein Ivy1 is an effector of the Rab7 GTPase Ypt7 involved in vacuole membrane homeostasis

Numrich, Johannes ; Péli-Gulli, Marie-Pierre ; Arlt, Henning ; Sardu, Alessandro ; Griffith, Janice ; Levine, Tim ; Engelbrecht-Vandré, Siegfried ; Reggiori, Fulvio ; De Virgilio, Claudio ; Ungermann, Christian

In: Journal of Cell Science, 2015, vol. 128, no. 13, p. 2278–2292

Membrane fusion at the vacuole depends on a conserved machinery that includes SNAREs, the Rab7 homolog Ypt7 and its effector HOPS. Here, we demonstrate that Ypt7 has an unexpected additional function by controlling membrane homeostasis and nutrient-dependent signaling on the vacuole surface. We show that Ivy1, the yeast homolog of mammalian missing-in-metastasis (MIM), is a vacuolar effector of...

Université de Fribourg

Lipid droplets are functionally connected to the endoplasmic reticulum in Saccharomyces cerevisiae

Jacquier, Nicolas ; Choudhary, Vineet ; Mari, Muriel ; Toulmay, Alexandre ; Health and Human Services, Bethesda, USA ; Reggiori, Fulvio ; Schneiter, Roger

In: Journal of Cell Science, 2011, vol. 124, p. 2424-2437

Cells store metabolic energy in the form of neutral lipids that are deposited within lipid droplets (LDs). In this study, we examine the biogenesis of LDs and the transport of integral membrane proteins from the endoplasmic reticulum (ER) to newly formed LDs. In cells that lack LDs, otherwise LD-localized membrane proteins are homogenously distributed in the ER membrane. Under these conditions,...