Integration and oligomerization of Bax protein in lipid bilayers characterized by single molecule fluorescence study.

J Biol Chem

Department of Pharmacology III and State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Shanghai 201203 and. Electronic address:

Published: November 2014

Bax is a pro-apoptotic Bcl-2 family protein. The activated Bax translocates to mitochondria, where it forms pore and permeabilizes the mitochondrial outer membrane. This process requires the BH3-only activator protein (i.e. tBid) and can be inhibited by anti-apoptotic Bcl-2 family proteins such as Bcl-xL. Here by using single molecule fluorescence techniques, we studied the integration and oligomerization of Bax in lipid bilayers. Our study revealed that Bax can bind to lipid membrane spontaneously in the absence of tBid. The Bax pore formation undergoes at least two steps: pre-pore formation and membrane insertion. The activated Bax triggered by tBid or BH3 domain peptide integrates on bilayers and tends to form tetramers, which are termed as pre-pore. Subsequent insertion of the pre-pore into membrane is highly dependent on the composition of cardiolipin in lipid bilayers. Bcl-xL can translocate Bax from membrane to solution and inhibit the pore formation. The study of Bax integration and oligomerization at the single molecule level provides new evidences that may help elucidate the pore formation of Bax and its regulatory mechanism in apoptosis.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4231651PMC
http://dx.doi.org/10.1074/jbc.M114.583393DOI Listing

Publication Analysis

Top Keywords

integration oligomerization
12
lipid bilayers
12
single molecule
12
pore formation
12
bax
10
oligomerization bax
8
molecule fluorescence
8
study bax
8
bcl-2 family
8
activated bax
8

Similar Publications

Background: Reports indicate that depression is a common mental health issue following traumatic brain injury (TBI). Our prior research suggests that Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)-related neuroinflammation, modulated by glial cells such as astrocytes, is likely to play a crucial role in the progression of anxiety and cognitive dysfunction. However, there is limited understanding of the potential of astrocytic NLRP3 in treating depression under mild TBI condition.

View Article and Find Full Text PDF

TDP43 autoregulation gives rise to dominant negative isoforms that are tightly controlled by transcriptional and post-translational mechanisms.

Cell Rep

January 2025

Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA; Graduate Program in Cell and Molecular Biology, University of Michigan, Ann Arbor, MI, USA; Medical Scientist Training Program, University of Michigan, Ann Arbor, MI, USA; Department of Neurology, University of Michigan, Ann Arbor, MI, USA. Electronic address:

The nuclear RNA-binding protein TDP43 is integrally involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Previous studies uncovered N-terminal TDP43 isoforms that are predominantly cytosolic in localization, prone to aggregation, and enriched in susceptible spinal motor neurons. In healthy cells, however, these shortened (s)TDP43 isoforms are difficult to detect in comparison to full-length (fl)TDP43, raising questions regarding their origin and selective regulation.

View Article and Find Full Text PDF

Elucidating the interaction between membrane proteins and antibodies requires whole-cell imaging at high spatiotemporal resolution. Lattice light-sheet (LLS) microscopy offers fast volumetric imaging but suffers from limited spatial resolution. DNA-based point accumulation for imaging in nanoscale topography (DNA-PAINT) achieves molecular resolution but is restricted to two-dimensional imaging owing to long acquisition times.

View Article and Find Full Text PDF

The complement system plays an integral role in both innate and adaptive immune responses. Beyond its protective function against infections, complement is also known to influence tumor immunity, where its activation can either promote tumor progression or mediate tumor cell destruction, depending on the context. One such context can be provided by antibodies, with their inherent capacity to activate the classical complement pathway.

View Article and Find Full Text PDF

Introduction: The Structural Basis of Virus Function.

Subcell Biochem

December 2024

Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), and Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain.

Viruses may be regarded as dynamic nucleoprotein assemblies capable of assisted multiplication within cells, and of propagation between cells and organisms. Infectious virus particles (virions) assembled in a host cell are dynamic, generally metastable particles: They are robust enough to protect the viral genome outside the cell but are also poised to undergo structural changes and execute mechanochemical actions required for infection of other cells. This chapter provides a broad introduction to the structural and physical biology of viruses and is intended mainly for virology students.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!