IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Starvation-induced autophagy causes a re-distribution of VAMP7 vesicles to focal adhesions in HeLa cells.Potrero d
Autor/es:
FADER, C.M.; COLOMBO M.I.
Reunión:
Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2011
Resumen:
Autophagy is a normal degradative pathway that involves the
sequestration of cytoplasmic components and organelles in a
vacuole called autophagosome which finally fuses with the
lysosome to degrade the sequestered material. The protein LC3 is an
autophagic marker present in eukaryotic cells which localizes to
autophagosomes. SNAREs are key molecules of the vesicle fusion
machinery. Our results indicate that a subset of Vamp7 (V-SNARE)-
positive vacuoles colocalize with LC3 at the cell periphery upon
starvation. Moreover, we have demonstrated that these Vamp7-
positive structures are labeled by paxillin and vinculin (focal
adhesion markers), indicating that the Vamp7-positive
autophagosomes are present in these structures. We have also shown
that the Vamp7 structures close to plasma membrane have late
endosomal characteristics. Interestingly, the re-distribution of
Vamp7 positive structures is a microtubule-dependent event, with
the participation of the motor protein Kif5 and a Rab7 effector RILP.
Furthermore, we have observed an increased number of ATP
vesicles labeled with Vamp7 at the focal adhesions upon starvation.
Taken together, our results suggest that VAMP7 is involved in the
trafficking of amphisomes, which contain ATP, to the focal
adhesions. It is likely that these structures may fuse with plasma
membrane to release the nucleotide to the extracellular medium.