Date Approved
1-26-2024
Embargo Period
1-25-2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy (Ph.D.), Pharmaceutical Chemistry
Department
Chemistry and Biochemistry
College
College of Science & Mathematics
Advisor
Zhihong Wang, Ph.D.
Committee Member 1
Subash Jonnalagadda, Ph.D.
Committee Member 2
Zhiwei Liu, Ph.D.
Committee Member 3
Hao Zhu, Ph.D.
Committee Member 4
Zhijun Li, Ph.D.
Keywords
BRAF Kinase, MAPK pathway, cell growth and division
Subject(s)
Protein kinases–Regulation
Disciplines
Biochemistry, Biophysics, and Structural Biology | Life Sciences
Abstract
BRAF kinase is a key member of the MAPK pathway, important for cell growth and division. Upstream signals promote BRAF activation by interaction with the membrane bound GTPase, RAS, which leads to relief of autoinhibition and dimerization. The N-terminal regulatory domains of BRAF, including the BRAF specific region (BSR), the RAS binding domain (RBD), and the cysteine rich domain (CRD), govern the conformational state of the cytosolic, autoinhibited monomer and drive the RAS-RAF interaction. Active BRAF phosphorylates and activates its substrate MEK, which in turn phosphorylates and activates ERK. Mutations in RAS and BRAF are the cause of many cancers and RASopathy developmental disorders; however, therapeutic approaches are limited due to challenges in BRAF and RAS inhibition and an incomplete understanding of BRAF and RAS biochemistry. Here, we shed light on the details of BRAF activation and interaction with RAS in three parts: 1) we investigated the roles of the BSR, RBD, and CRD in regulating the RAS-RAF interaction and membrane recruitment; 2) we developed chemical probes to disrupt the RAS-RAF interaction and eliminate MAPK signaling in cancer; and 3) we elucidated the intramolecular interactions involved in RAF autoinhibition. Our findings point to unique contributions of each BRAF N-terminal domain in the regulation of autoinhibition and in determining isoform-specific RAS interactions.
Recommended Citation
Trebino, Tarah, "Unveiling the Unique RAS Isoform and Domain Specific Regulation of BRAF Kinase" (2024). Theses and Dissertations. 3189.
https://rdw.rowan.edu/etd/3189
