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Keywords

Biophysics, proteins, exocytosis, SNARE complex

Abstract

In the brain, neurons communicate via releasing and detecting neurotransmitters. Release occurs through exocytosis, following fusion of synaptic vesicles to neuronal cell membranes. This process is driven by formation of a dynamic quaternary protein structure known as the SNARE complex. SNAP-25 contributes two alpha helical domains to this complex. Neurons express SNAP-25 in two distinct isoforms, SNAP-25A (25A) and SNAP-25B (25B). These two isoforms vary by only 9 amino acids and are expressed differently depending on brain region and the developmental stage of the neuron [1]. The primary structures of 25A and 25B and their effect on SNARE complex formation have been studied [2]. However, the difference in secondary structures of 25A and 25B are still being explored. Using circular dichroism (CD) spectroscopy, we illustrate differences in the secondary structure of 25A and 25B following exposure to a variety of environmental conditions and other factors. We show that temperature, redox state, and alcohol differentially alter the secondary structure of SNAP-25 isoforms. Although 25A and 25B function similarly under normal physiological conditions, we hypothesize that the differences observed provide the cell with appropriate responses under different environmental stresses. During different stages of development and in different regions of the brain, neurons presumably select the isoform that best meets the cell’s needs.

Document Type

Poster

Publication Date

2024-03-21

Language

English

College

Life Sciences

Department

Cell Biology and Physiology

University Standing at Time of Publication

Senior

Changes in Environmental Conditions Affect the Two Isoforms of SNAP-25 Differently

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