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dc.contributor.advisorWalensky, Loren D
dc.contributor.authorBloch, Noah Benjamin
dc.date.accessioned2022-03-18T04:22:57Z
dash.embargo.terms2023-03-17
dc.date.created2022
dc.date.issued2022-03-17
dc.date.submitted2022-03
dc.identifier.citationBloch, Noah Benjamin. 2021. Mechanistic Insights into the Conformational Regulation of Pro-Apoptotic BAX. Doctoral dissertation, Harvard University Graduate School of Arts and Sciences.
dc.identifier.other28963878
dc.identifier.urihttps://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37371142*
dc.description.abstractBCL-2 family proteins are apoptotic regulators that control the critical balance between cellular life and death at the level of the mitochondrion. BAX is a principal executioner of apoptosis, transforming from a latent cytosolic monomer into a lethal mitochondrial oligomer in response to cell stress. Because renegade BAX activation poses a grave risk to the cell, the architecture of BAX must ensure monomeric stability yet enable conformational transformation. The specific structural features that afford both stability and dynamic flexibility remain ill-defined and represent a critical control point of BAX regulation. In this dissertation, I identified a nexus of interactions involving discrete residues of BAX’s core a5 helix, specifically amino acids 113-116, which are individually essential to maintaining the structural stability of monomeric BAX and are collectively required for higher order BAX assembly. Single alanine mutagenesis of residues 113-116 resulted in autoactive proteins that were capable of membrane permeabilization even in the absence of BH3-only ligand stimulation, which otherwise induces the activation of wild-type BAX. Analysis of conformational dynamics by hydrogen deuterium exchange mass spectrometry revealed regiospecific changes in BAX structure, providing a mechanism for mutant autoactivity. Further, combinatorial mutagenesis of the BAX 113-116 nexus revealed the collective role of these residues in stabilizing the dimeric form of BAX, which represents a key step of oligomeric self-assembly. The dual yet distinct roles of BAX residues 113-116 highlight the intricacy of BAX conformational regulation and opportunities for modulating BAX conformational dynamics for therapeutic benefit in diseases of deregulated apoptosis.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dash.licenseLAA
dc.subjectApoptosis
dc.subjectBAX
dc.subjectCell Death
dc.subjectBiochemistry
dc.subjectBiology
dc.subjectMolecular biology
dc.titleMechanistic Insights into the Conformational Regulation of Pro-Apoptotic BAX
dc.typeThesis or Dissertation
dash.depositing.authorBloch, Noah Benjamin
dash.embargo.until2023-03-17
dc.date.available2022-03-18T04:22:57Z
thesis.degree.date2021
thesis.degree.grantorHarvard University Graduate School of Arts and Sciences
thesis.degree.levelDoctoral
thesis.degree.namePh.D.
dc.contributor.committeeMemberKing, Randall
dc.contributor.committeeMemberArthanari, Haribabu
dc.contributor.committeeMemberSteen, Hanno
dc.contributor.committeeMemberHardwick, J. Marie
dc.type.materialtext
thesis.degree.departmentMedical Sciences
dc.identifier.orcid0000-0002-9121-2783
dash.author.emailnoah.bloch25@gmail.com


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