NSF Postdoctoral Fellowship in Biology FY 2017: Cellular mechanisms for preferential intracellular pH regulation

Roa Jinae N, La Jolla CA

Investigators

Abstract

This is an NSF Postdoctoral Research Fellowship in Biology, under the program Broadening Participation of Groups Under-represented in Biology. The fellow, Jinae Roa, is conducting research and receiving training that is increasing the participation of groups underrepresented in biology. The fellow is being mentored by Colin Brauner at the University of British Columbia. The fellow is investigating how animals use signals produced by individual cells to maintain proper function of vital organs like the heart, skeletal muscle, and liver. The research focuses on cellular mechanisms used by fish from naturally extreme environments, and the results will provide critical information on how animals sense and repair conditions that negatively affect organ function. During outreach activities, the fellow is supporting the diverse local community by volunteering as an educator for an inner-city Science 101 program and by leading interactive hands-on activities at the Vancouver Aquarium. In addition, the fellow is training and mentoring graduate and undergraduate students. Upon completion of fellowship activities, the fellow will seek employment at a US institution whose primary mission includes increasing and sustaining diversity, where the fellow can serve as a role model and mentor for young women and students from underrepresented groups. The primary aim of this study is to investigate for the first time the cellular mechanisms responsible for sensing and regulating intracellular pH (pHi) in fish that preferentially regulate tissue pHi instead of blood extracellular pH (pHe). Limiting acid-base stress is an important function of vertebrate physiological systems as it reduces harmful exposure to hydrogen ions (H+), which negatively affect essential functions such as metabolism. However, information is lacking on the mechanisms by which pHi is sensed, what ion channels are involved, and if there is any whole-animal hormonal influence on preferentially regulated tissues. To address these questions, the fellow is investigating acid-base sensors in whole tissues in a fish species that is a preferential pHi regulator (white sturgeon, Acipenser transmontanus). In addition, the fellow is creating primary cultures of cells isolated from heart, muscle, and liver tissues of white sturgeon to study mechanisms for acid-base sensing and regulation, testing the following hypotheses: (1) preferential pHi regulation is facilitated by the evolutionarily conserved acid-base sensor soluble adenylyl cyclase (sAC), Na+/H+ exchanger (NHE), and Na+/HCO3- cotransporter (NBC); and (2) preferential pHi regulation is influenced by whole-animal processes and thereby reduced in cultured cells.