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Steven O. Marx, M.D.

Professor of Medicine - Cardiology, Pharmacology, and Professor of Physiology & Cellular Biophysics

Molecular biology/macromolecular complex formation of ion channels.


The Marx Lab studies the regulation of ion channels by macromolecular complexes. We have demonstrated that specific sequences within the ion channel (leucine zippers) recruit regulatory proteins, which modulate the ion channel function in normal and pathologic conditions. The laboratory is now focused on understanding the molecular components and functional implications of macromolecular complex formation of the large conductance calcium-activated potassium channel (BKCa, maxi-K) and the L-type voltage gated calcium channel. The laboratory utilizes both molecular biologic and electrophysiologic (planar lipid bilayer, patch clamp) techniques to elucidate these fundamental processes and emphasizes the links between these fundamental molecular processes and systems function. To date our work has had significant impact in understanding the triggers of fatal cardiac arrhythmias and mechanical dysfunction in heart failure. Present experiments are very likely to impact our understanding of control of peripheral blood pressure by the sympathetic nervous system.

The Marx Lab collaborates with the Wan Lab and the Morrow Lab to develop new methods of diagnosing and treating arrhythmias. Our scientists have made major advances in understanding the molecular and cellular bases for and the fundamental mechanisms of complex, life-threatening arrhythmias and sudden cardiac death. Our research program is focused in two major areas:

  • Cardiac: studying the regulation of ion channels in normal and pathological conditions in the heart. Altered cardiac ion channel function is associated with heart failure and arrhythmias.

  • Vasculature: understanding molecular mechanisms leading to vascular smooth muscle proliferation, migration, and contractility.

    Our combined mission is to promote and stimulate interdisciplinary research in the cardiovascular field, with the overall goal of developing new and effective approaches for the diagnosis and treatment of diseases of the heart and blood vessels and the prevention of premature death.


Selected Publications


Kushner JS, Liu G, Eisert RJ, Bradshaw GA, Pitt GS, Hinson JT, Kalocsay M, Marx SO.  Detecting Cardiovascular Protein-Protein Interactions by Proximity Proteomics.

Circ Res. 2022 Jan 21;130(2):273-287. doi: 10.1161/CIRCRESAHA.121.319810. Epub 2022 Jan 20.PMID: 35050691 


Redel-Traub G, Liu G, Marx SO, Kushner J. Probing ion channel neighborhoods using proximity proteomics..  Structure. 2021 Aug 26:S0969-2126(21)00296-3. PMID: 34469755 

Methods Enzymol. 2021;654:115-136. doi: 10.1016/bs.mie.2021.01.027. Epub 2021 Mar 22.PMID: 34120710

Roybal D, Hennessey JA, Marx SO.  Structural Basis for Gating and Activation of RyR1. Channels (Austin). 2020 Dec;14(1):123-131. doi: 10.1080/19336950.2020.1740502.PMID: 32195622 


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