Scientific Reports

Scientific Report 2008-2010 for the Laboratory of Olivier Vincent -

Role of arrestins in intracellular trafficking in Saccharomyces cerevisiae

Group Leader
Vincent -, Olivier
Graduate Students
Herrador Fernández, Antonio
Izquierdo Pascual, Elena (from Jul 2009 )
Collaborations
Orozco , Esther. CINVESTAV, México
Undergraduate Students
Lara Astiaso, David
Martínez Calle, Marta
Bullejos Peregrín, Javier

Research topics

Interaction network of arrestin-related proteins in Saccharomyces cerevisiae

( Lara, D. , Izquierdo, E. , Vincent, O. )


 

Arrestins plays a key role in the regulation of the seven-transmembrane-spanning (7TM) receptors in mammals. These receptors, on the other hand, are involved in a large number of physiological processes and are the target of 40% of the therapeutical drugs. A large number of studies showed that arrestins play a key role in the intracellular traffic of 7TM receptors. Our previous results indicate that the function of the arrestin-related proteins that we have identified in the model organism Saccharomyces cerevisiae is also related to intracellular traffic. In addition, our results demonstrate that the molecular mechanisms involved in the regulation of arrestin function in intracellular traffic in mammals are conserved in S. cerevisiae. Our main goal is to explore the function of these proteins in S. cerevisiae. The results of this study should reveal important aspects of the regulation of these proteins, conserved  throughout the evolution. In an attempt to identify the cellular process in which these proteins participate, we carried out two-hybrid screenings with several members of this protein family and tested the role of arrestin domains in protein-protein interaction. Results obtained suggest that yeast arrestin-related proteins are potential hub proteins linking plasma membrane transporters to the endocytic machinery and nutrient signaling pathways.


Recruitment of the ESCRT Machinery to a Putative Seven-Transmembrane-Domain Receptor Is mediated by an Arrestin-Related Protein

( Herrador, A. , Bullejos, J. , Martínez, M. , Vincent, O. )


 

Mammalian arrestins have a major role in the intracellular trafficking of seven-transmembrane (7TM) receptors. The fungal ambient pH signaling pathway involves an arrestin-related protein, PalF/Rim8, and the ESCRT (endosomal sorting complex required for transport) machinery. We found that in Saccharomyces cerevisiae, Rim8 binds to the 7TM protein, the putative pH sensor Rim21, and the ESCRT-I subunit Vps23. We showed that an SXP motif in Rim8 mediates binding to the Vps23 ubiquitin E2 variant (UEV) domain and that a monoubiquitinated residue near the SXP motif contributes to this interaction. Rim8 ubiquitination is dependent on the Rsp5 E3 ubiquitin ligase and triggered upon binding of Vps23 UEV to both the SXP motif and ubiquitin, thus suggesting a two-step binding mechanism. We further showed that Rim8 coimmunoprecipitates with ESCRT-I subunits Vps23 and Vps28, supporting the idea that binding of Rim8 to Vps23 mediates the association of Rim8 with the ESCRT-I complex. Fluorescence microscopic analyses indicate that overexpressed Rim8 and Vps23 colocalize at cortical punctate structures, providing additional evidence of the interaction between these two proteins. Strikingly, our findings indicate that evolutionary conserved mechanisms control the recruitment of the ESCRT machinery to Pal/Rim proteins in fungi and retroviral Gag proteins in animal cells.

Publications

Herrador, A. , Herranz, S. , Lara, D. , Vincent, O. (2010). Recruitment of the ESCRT machinery to a putative seven-transmembrane-domain receptor is mediated by an arrestin-related protein. Mol. Cell. Biol. 30(4): 897-907.


(2010). Detection of the Endosomal Sorting Complex Required for Transport in Entamoeba histolytica and Characterization of the EhVps4 Protein. J Biomed Biotechnol. .

Financial Support
Olivier Vincent -


“Localización subcelular de las proteínas implicadas en la recepción de la señal de pH ambiental en Saccharomyces cerevisiae .” Financiado por: CAM-CSIC. Year 2008-2008


Olivier Vincent -


“Análisis funcional de proteínas relacionadas con las arrestinasa en Saccharomyces cerevisiae.” Financiado por: CAM-CSIC. Year 2009-2009


Olivier Vincent -


“Función de las arrestinas en tráfico intracelular en saccharomyces cerevisiae .” Financiado por: CICYT. Year 2009-2011