How is Motor-Driven Transport Regulated?
Active transport of intracellular cargoes occurs widely in cells. One major system to accomplish
this task is motor-driven transport along microtubules.
Although the properties of single motors have been extensively studied in
vitro, it is still mysterious how motors are regulated in vivo and how multiple
motors are coordinated with each other and with other cellular processes. We
are interested in how cells control the activity and specificity of microtubule
motors and how multiple motors function together.
We study this problem using Drosophila. Our main focus is on organelle
transport in the early embryo. In this experimental system, one can not
only observe the motion of organelles directly, but can also manipulate
the motors and regulators genetically. We are using biochemical approaches
and genetic screens to identify the molecules involved in this transport.
Currently, we are in the process of molecularly characterizing two potential
regulators of transport directionality, Halo and OWS. One regulator, Klar,
is expressed widely during development and enables both a switch in transport
direction and appears to be necessary for coordinating multiple motors.
Collaboratively, we determine how our mutations affect the biophysical
properties
of motion and to what extent they alter RNA trafficking.
We are also investigating whether the molecules and principles we are uncovering
in embryos apply to other motor-based transport processes in the fly, such
as the migration of nuclei in developing neurons and axonal transport. Finally,
we are exploiting the technical advantages of Drosophila embryos to investigate
a novel mechanism for controlling the activity of proteins, developmentally
programmed protein aggregation.
To learn more:
Go to Research Interests - Details
S.P. Gross, Y. Guo, J.E. Martinez, M.A. Welte (2003).
"A Determinant for Directionality of Organelle Transport in Drosophila Embryos".
Curr. Biol. 13:1660-1668. Abstract
S. P. Gross, M. A Welte, S. M. Block, E. F. Wieschaus (2002).
"Coordination of opposite-polarity microtubule motors".
J. Cell Biol. 156:715-724. Abstract
S. P. Gross, M. A Welte, S. M. Block, E. F. Wieschaus (2000).
"Dynein-mediated cargo transport in vivo. A switch controls travel distance".
J. Cell Biol. 148:945-956. Abstract
M. A. Welte, S. P. Gross, M. Postner, S. M. Block, E. F. Wieschaus (1998).
"Developmental regulation of vesicle transport in Drosophila embryos:
forces and kinetics".
Cell 92:547-557. Abstract
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