Biology Seminar Series - Hijai Regina Shin - “Lysosome at the center of sterol sensing and growth regulation”

“Lysosome at the center of sterol sensing and growth regulation”

Hijai Regina Shin,

University of California Berkeley, Department
of Molecular and Cell Biology

💡Dr. Shin’s research interest revolves around understanding the lysosome as the center for
nutrient sensing and cellular quality control, with emphasis on the signaling pathways
mediated by cholesterol and its derivatives and how these molecules govern cellular
growth and other important cellular decisions in health and disease.
The lysosome has long been known as the endpoint of multiple catabolic processes but an
increasing body of work shifted our rather simplistic view of the lysosome to a view in
which the lysosome is the central node of a sophisticated network for cellular adaptation.
Indeed, the lysosome is a center for nutrient sensing and metabolic regulation via its
physical and functional association with the master growth regulator mTORC1 kinase.
Cholesterol, a key building block for cellular membranes and a precursor for steroid
hormones, was recently identified as a major nutrient input that activates mTORC1. Dr.
Shin will present her most recent work on the identification of a novel lysosomal
transmembrane protein as an essential factor that enables cholesterol-dependent
activation of mTORC1. This work identified the first candidate sensor linking cholesterol to
growth regulation, which is distinct from SCAP-SREBP pathway at the ER functioning as a
“homeostatic” sensor and fills a critical gap in our knowledge of mTORC1 biology and of
cholesterol signaling. She will also present recent effort to develop novel approaches to
pharmacologically manipulate mTORC1 activity that could be more specific and effective
than currently available mTORC1 inhibitors.

Host: José Dinneny and Ron Kopito