Marisa Otegui

Membrane remodeling for protein degradation and cell signaling

The Otegui laboratory analyzes membrane remodeling events connected to protein degradation in plant cells. More specifically, we are working on ESCRT (Endosomal Sorting Complex Required for Transport) and reticulon proteins in the context of two projects: 1) the formation of endosomal vesicles that mediate the degradation of plasma membrane proteins; and 2) the fragmentation of large organelles, such as the endoplasmic reticulum, during their autophagic turnover. For these studies, we combine genetics, biochemical, and state-of-the-art imaging approaches, such as electron tomography.

Formation of intralumenal vesicles in plant multivesicular endosomes (MVE) and simulation of cargo (membrane proteins) escape. (A) Tomographic reconstruction of a plant MVE. (B) Detail of an interconnected network of vesicle buds. (C) Schematic representation of the network shown in (B). Asterisk indicate the vesicle bud connected to the limiting membrane of the MVE. (D) Model of vesicle bud concatenation. Asterisks indicate an early stage in membrane bending during vesicle formation. (E) Geometries of vesicle buds derived from electron tomograms used for the cargo diffusion simulations depicted in (F). The green shaded area corresponds to the region where the cargo molecules (40 particles representing the auxin efflux carrier PIN2) were placed to start the simulation. (F) Simulated escape times of 40 PIN2 particles placed on the lower hemisphere of the vesicle bud using a diffusion coefficient of 0.17 mm². Colored lines indicate the mean number of remaining cargo particles over time from over 300 simulations and the shaded region corresponds to the standard deviation. See Buono et al (2017) for more details (Scale bars= 50 nm).

Lab website

Representative publications:

Buono, R.A., Leier, A., Paez-Valencia, J., Pennington, J., Goodman, K., Miller, N., Ahlquist, P., Marquez-Lago, T., Otegui, M.S. 2017. ESCRT-mediated vesicle concatenation in plant endosomes. Journal Cell Biology 216: 2167-2177.

Buono, R., Paez Valencia, J., Miller, N.D., Spitzer, C., Spalding, E.P., Otegui, M.S. 2016. Role of SKD1 regulators LIP5 and IST1-LIKE 1 in endosomal sorting and plant development. Plant Physiology 171: 251-264.

Spitzer, C. Li, F., Buono, R., Roschzttardtz, H., Chung, T., Zhang, M., Osteryoung, K.W., Vierstra, R.D., Otegui, M.S. 2015. The Endosomal Protein CHARGED MULTIVESICULAR BODY1 Regulates the Autophagic Turnover of Plastids in Arabidopsis. Plant Cell 27:391-402.

Reyes, F.C., Buono, R.A. Roschzttardtz, H., Di Rubbo, S., Yeun, L.H., Russinova,E. Otegui, M.S. 2014. A novel endosomal sorting complex required for transport (ESCRT) component inArabidopsis thaliana controls cell expansion and development. Journal Biological Chemistry 289: 4980-4988.