CURF: Investigating Disease-Causing Mutations in the Renal Outer Medullary Potassium Channel Protein

This semester, I will be given the incredible opportunity to continue studying various identified human disease-causing mutations of the renal outer medullary potassium (ROMK) channel protein located in the epithelial cells of the kidney. I will be conducting my research alongside my mentor, Katie Nguyen, in Dr. Jeffrey Brodsky’s lab within the Biological Sciences department at the University of Pittsburgh. Ultimately, the main goal of my project is to experimentally assess and characterize the functional impact of multiple different human missense mutations of ROMK in the model organism yeast (Saccharomyces cerevisiae). Most importantly, my research will emphasize several Bartter disease-causing mutations of ROMK. 

To provide some background information regarding this life-altering disease, Bartter disease is a group of inherited kidney disorders characterized by an imbalance in potassium and other electrolytes. Notably, individuals with Bartter disease often suffer from a wide range of debilitating symptoms, including muscle weakness, chronic fatigue, and excessive thirst and urination. A certain form of the disease, Bartter disease type II, is known to be caused by mutations in ROMK that essentially lead to the premature degradation of this vital protein. Alarmingly, there is currently no cure for this devastating disease. Furthermore, it has been discovered that ROMK also plays a secondary role in overall human health. Specifically, individuals with only one defective copy of this protein are protected against hypertension (high blood pressure). With complications caused by hypertension being one of the leading causes of death in the United States, it is of even greater urgency that we further understand ROMK function. 

To this end, I have already employed computational methods to analyze an original list of known ROMK mutations in a human genome database of individuals with heart, lung, sleep, and blood disorders. From this initial analysis, I have selected 17 missense mutations in ROMK, 12 of which are associated with Bartter disease. I performed growth assays of yeast transformed with wild-type or one of 17 missense ROMK variants on both solid medium and liquid medium supplemented with high potassium and low potassium. Based on the results of these growth assays, I have narrowed down a list of 5 mutations that I will further characterize by employing diverse molecular, cellular, and biochemical techniques in yeast and human cell culture to experimentally assess the defects of these mutants. Explicitly, I will perform cycloheximide chase assays and western blot assays to further assess the stability of several ROMK variants of interest. Ultimately, this study will aim to reveal the amino acids that are critical for protein function and stability and hopefully bring the world one step closer to uncovering the complex genetics behind life-threatening conditions such as Bartter syndrome type II and hypertension.

To elaborate on my personal professional goals, I plan to merge my passion for science and my desire to serve people by pursuing a career in genetic counseling. As an aspiring medical professional, I am extremely thankful that the Chancellor’s Undergraduate Research Fellowship has granted me the wonderful opportunity to share my science as I progress through my research project. Overall, this fellowship experience will enhance my passion for research while simultaneously allowing me to gain more insight into current events within the medical community. As this is my second experience with CURF, I am beyond excited to see how my classmates and I grow as scientists throughout the semester!

A little bit about me: 

  • Major: Biological Sciences
  • Minors: Chemistry and Administration of Justice 
  • I’m a founder of a new club at Pitt called Bridge Beyond! The main mission of this club is to provide resources for individuals experiencing homelessness in the Pittsburgh area. 

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