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New Biological Frontiers Illuminated by Molecular Sensors and Actuators
Poster Abstracts
52-POS
Board 52
Chemical Biology Sensors for Membrane Curvature and Lipid Composition
Hang Yin
.
University of Colorado Boulder, Boulder, USA.
Elevated microvesicle (MV) shedding is an indication of cancer metastasis. Selectively sensing
the highly curved membrane of MVs may provide a novel strategy for their detection, which
renders the potential of developing diagnostic, prognostic, and therapeutic agents. We employed
a multidisciplinary approach, utilizing our expertise in computational modeling, membrane
biophysics, and cellular assay development to rationally design novel tools that sense and
regulate membrane curvature and lipid components. Curved membranes are a common and
important attribute in exosomes and microvesicles. Our interest focuses on identifying and
designing peptides that can sense membrane curvature based on established elements observed in
natural curvature-sensing proteins. We have successfully identified a 25-mer peptide, MARCKS-
ED, as well as its D-isomer that can both recognize PS with preferences for highly curved
vesicles in a specific manner. These rationally designed agents not only help us to understand the
critical protein-lipid interactions but also provide prototypes that may eventually lead to novel
cancer biomarkers. These studies provide coveted specific probes for exosomes and
microvesicles that may be of diagnostic and prognostic potentials.
53-POS
Board 53
RFP Tags for Labeling Secretory Pathway Proteins
Mingshu Zhang
, Pingyong Xu.
Institute of Biophysics,Chinese Academy of Sciences, Beijing, China.
Many RFPs are prone to form artificial puncta when labeling proteins in secretory pathway,
which may severely impede their further uses in living cell imaging and multi-color imaging.
Here we used an environment sensitive membrane protein Orai1 to report the fusion properties of
several commonly used RFPs and revealed that intracellular artificial puncta are actually
colocalized with lysosome, indicating pKa value of RFPs is also a key factor for artificial puncta
appearance besides monomeric properties. In summary, our current study established a fast and
easy method to evaluate RFPs fusion properties and provides a useful guide for choosing
appropriate RFP for labeling secretory membrane proteins. Among RFPs tested, mOrange2 is
highly recommended based on excellent monomeric property, appropriate pKa and high
brightness.