Project Summary/Abstract
G protein coupled receptors (GPCRs) control the majority of cellular signaling; both physiological and pathological.
Activated GPCRs induce heterotrimer dissociation, generating active GaGTP and Gß¿. Generated Gß¿ controls effectors in
multiple signaling pathways. GPCRs and G proteins based chemokine pathway is crucial for proper cellular functions
including migration and growth and is highly implicated diseases including cancer. Cancer cells employ chemokine pathway
to hijack growth factor receptor (GFR) signaling, primarily through Gß¿, which has the propensity to control cell adhesion,
migration and invasion, facilitating metastasis. Although there are 48 members in the family, Gß¿ is often considered a
unitary signaling entity. However, our provocative data show that, the 12 G¿ types differently govern the PM affinity of
Gß¿, regulating the efficacy of Gß¿ signaling in a G¿ identity dependent manner.
In Aim 1, we will establish molecular mechanisms that allow G¿ subunits to possess their carboxy terminus (CT)
identity specific PM affinities. In Aim 2, we will seek mechanisms by which PM affinity of G¿ subunits control the efficacy
of Gß¿ effector activation and regulation of chemokine signaling in triple negative breast cancer (TNBC) cells. In Aim 3 of
the proposal, we will examine the role of PM affinity of G¿ and hence he PM-bound fraction of free Gß¿ in regulation of
signaling that govern adhesion, migration and invasion of TNBC cells.
This project is designed to train and employ undergraduate and graduate students, and uses innovative subcellular
optogenetic methods to control signaling, high resolution confocal as well as total internal reflection fluorescence (TIRF)
microscopy to monitor signaling and cell behaviors, novel–unbiased image and data analysis methods to extract data, state-
of-the-art genome editing methods to alter the PM affinity of native G¿ in TNBC cells. The proposed work will provide the
first analysis of GPCR-G protein signaling regulation by the G¿ subtype specific PM affinities of Gß¿ in breast cancer cells.
Our goal is to deliver the molecular process that controls G¿-PM interactions as a new molecular target governing cancer
cell adhesion, migration and proliferation.
