Dissecting the Diverse Roles of Importin α at the Plasma Membrane

Project Summary
What spatial and temporal controls regulate subcellular macromolecular complexes at
the cell surface (plasma membrane) and how such spatial and temporal controls impact
various disease states, is not known. The long-term goal of this proposal is to find new
targets for diagnostic and treatment approaches that address the subcellular changes
that occur in macromolecular complexes at the plasma membrane in diseases ranging
from cancer, ciliopathies such as polycystic kidney disease, and various neuropathies.
The objective of this proposal is to assess the novel role of a key protein in tethering
numerous factors to the plasma membrane to precisely control the location and timing
of the formation of subcellular complexes involved in cell division, growth signaling and
nerve signaling transduction. The proposal will use an innovative combination of
techniques from biological, physical and biochemical sciences. These include recently-
in-house-developed techniques using microfluidics and optogenetics to encapsulate
cytoplasm in various sizes of our choosing in which the membrane composition, cell
cycle state, and protein composition can all be precisely controlled both spatially and
temporally. The proposed research is significant, because it will determine which
proteins in these newly identified pathways should be therapeutic targets for which
diseases and in which cell types. It is also significant because it will develop a platform
that can be extended to other proteins to study their roles at the plasma membrane
alone or in combination with other factors, opening new avenues for dissecting
macromolecular complexes at the plasma membrane in various contexts. This work will
develop foundational resources that will be used by other researchers. The results will
have a positive impact immediately because they will establish a better understanding
of various cancers, ciliopathies and neuropathies and lead to new diagnostic and
therapeutic targets for these diseases, and long-term because they lay the groundwork
to develop new techniques for dissection of a multitude of different complexes at the
plasma membrane.

Grant Number: 5R35GM147569-04
NIH Institute/Center: NIH
Principal Investigator: Christopher Brownlee