NaAtm1: Studying a Heavy‐Metal ABC Transporter System

Abstract

Adenosine Triphosphate Binding Cassette (ABC) Transporters are a superfamily of integral membrane proteins that have been found embedded in both the cellular membranes and internal organelles of all species yet analyzed. This extreme conservation throughout the tree of life is due to their vitally critical and broad task of transporting all manner of things into and out of the cell and related organelles. This broadness of responsibility has led to an abundant diversity of this family, which in turn, has allowed life to adapt to the many environments found on Earth. While the importance and variability of this family is abundantly clear, many mechanistic and regulatory questions remain. The diversity which has made this family so useful in the natural world has resulted in a huge challenge in the scientific world: elucidating the many mechanisms this family has developed to perform its many functions. The scientific community has so far been able to identify overarching features of all ABC transporters such as the Walker A and Walker B motifs; however, the mechanisms of individual transporters remain undiscovered. In our research, we focus on a specific ABC transporter called NaAtm1 (Novosphingobium aromaticivorans ABC transporter of mitochondria 1), which has been shown to mediate transition metal export in its host species.While some transition metals (e.g. iron and copper) are essential for certain cellular processes such as respiration and enzyme catalysis, other metals (e.g. cadmium and mercury) can be very toxic to life. Due to this extreme dichotomy, a cell's ability to distinguish between friend and foe is of the utmost importance, and therefore should be a highly regulated process. Our goal is to better understand the full mechanism of the NaAtm1 transporter, to determine why it exports some metals while leaving others alone, and to understand the regulatory process that controls it. Toward this goal, we are conducting site‐directed mutagenesis, Fluorescent spectroscopy, and quantitative analyses of the NaAtm1 transport system. Here we present our preliminary work on examining NaAtm1 transport activity of substrates.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.