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Archives of Industrial Biotechnology | Volume 2
May 14-15, 2018 | Montreal, Canada
World Yeast Congress
Yeast dynamin (Vps1) has been implicated in recycling traffic
from the endosome to the trans-Golgi network (TGN). We
previously revealed a genetic interaction of Vps1 with Ypt6 and
all components of the GARP tethering complex that anchors an
incomingvesicletoTGNmembrane. Thepresent study identified
a 33 amino acid segment of Vps51, aGARP subunit that interacts
withVps1. Based on sequence homology betweenVps51 and its
mammalian homolog Ang2; we identified two key residues of
Vps51, E127 and Y129 that bind Vps1. The replacement of these
residues led to severe defects in endosome-to-TGN transport of
Snc1, providing evidence of the physiological relevance of the
interaction of Vps51 with Vps1 for the traffic. Furthermore, our
functional analysis revealed that Vps1 acts upstream of Vps51
and that the absence of Vps1 resulted in defects in targeting
of Vps51 and its binding partner Tlg1 to the TGN. The present
study also reveals that Vps1 physically interacts with Ypt6.
Interestingly, severe defects in retrograde trafficking caused by
loss of Ypt6 were rescued by overexpression of Vps1 and vice
versa. Furthermore, overexpression of Vps1 GTPase mutants
was not sufficient enough to rescue abnormal Snc1 recycling
in ypt6Δ cells. These results suggest that the GTP binding and
hydrolysis of Vps1 is essential for this trafficking pathway and
that Vps1 and Ypt6 may function parallel. Finally, this study
shows that Vps1 interacts with two SNARE proteins, Vti1 and
Snc2, functioning for endosome-derived vesicle fusion at
the TGN, pointing to a novel role of Vps1 in the late stage of
the endosome-to-Golgi traffic. Therefore, we propose that
Vps1 and Ypt6 converge on the GARP tethering machinery for
efficient tethering/fusion at the TGN.
Speaker Biography
Kyoungtae Kim is a Professor at Missouri State University in Springfield, MO. He
received his BA and MA in Biological Science at Kyungpook National University in Taegu,
Korea. He went on to obtain his PhD in Biology at Florida State University in Tallahassee,
Florida, and completed his Post-Doctoral at Washington University in St. Louis, Missouri,
where he studied Cell Biology and Physiology. He is now located at Missouri State
University where his research focuses on Diverse Cellular Processes including Endocytic
Pathway, Intracellular Trafficking of Proteins and Membranes, Membrane Organization,
Nanomaterial Traffic and Nanomaterial-Mediated Global Gene Expression Pattern
Changes.
e:
Kyoungtae Kim
Missouri State University, USA
Yeast dynamin plays a key role in the Endosome-to-Golgi traffic