The proposal aims the reintegration of a senior post-doctoral researcher of Spanish nationality, Dr. Marta Rubio-Texeira, now working at the Whitehead Institute (MIT, Cambridge, MA, USA), into the European research area at VIB/KULeuven in Belgium. Dr. Rubio-Texeira has advanced knowledge and extensive technical know-how on molecular mechanisms involved in plasma membrane protein trafficking and internalization in yeast, in the use of yeast as a tool to study proteins involved in neurodegenerative diseases and in the biotechnology of lactose fermentation. She will be integrated into the VIB department of Molecular Microbiology, located at the KULeuven, as a senior post-doctoral researcher, with committed support of the FWO Flanders for her initial appointment. With her experience she will strenghten the world leading research at this department into the molecular genetics and biochemistry of nutrient sensing and signaling in yeast. She will concentrate her work on the functioning of Gap1, an amino acid transporter that also functions as an amino acid sensor for activation of the protein kinase A (PKA) pathway in yeast. Gap1 is the best established example in eukaryotic cell biology of an actively transporting nutrient carrier that also functions as a receptor protein (‘transceptor’). She will investigate the relationship between Gap1 mediated amino acid activation of the PKA pathway and the rapid amino acid induced downregulation of Gap1 by dephosphorylation, ubiquitination, internalization and degradation. The latter is reminiscent of ligand-induced downregulation that occurs in many classical receptor proteins. In the second part of her work she will focus on elucidation of the components in the signaling pathway between Gap1 and PKA. The research on yeast nutrient sensing and signaling is a long-term goal in the VIB department of Molecular Microbiology and thus offers the possibility of permanent integration into the European Research Area.