INVESTIGADORES
RODRIGUEZ Fernanda Mariana
congresos y reuniones científicas
Título:
Function and Regulation of Arf1p
Autor/es:
RODRIGUEZ FERNANDA; SPANG ANNE
Lugar:
Heidelberg
Reunión:
Encuentro; Quantitative Analysis of Dynamic Processes in Membrane Transport and Translocation; 2008
Resumen:
The ArfGAP Glo3p is required for COPI vesicle generation in the Golgi-ER shuttle. The best-characterized role of Glo3p is the stimulation of the GTPase activity of Arf1p. Here we characterized the different domains of the ArfGAP Glo3 and identified a predicted helix-loop-helix motif in the central part of Glo3p, which is required for binding to both coatomer and cargo. The GAP domain together with the central part, are necessary and sufficient to fulfil all vital Glo3 functions. Expression of a GLO3 construct lacking the GAP domain results in dominant-negative growth phenotype in a delta glo3 strain at 37°C. This phenotype was rescued by mutating either the coatomer/ SNARE/ cargo binding domain or the Glo motif or by overexpression of ER-Golgi SNAREs, Gcs1 or Glo3. Since the Glo motif is not essential for Glo3 function, it may act as an intrinsic sensor coupling GAP activity to SNARE/cargo binding avoiding dead-end complex formation at the Golgi membrane, which may have detrimental effects. Our data demonstrate that the sensing of membrane and cargo evolved differently in ArfGAP1 and ArfGAP2/3 class of proteins.