Michael J. Rindler

The eukaryotic cell must segregate its proteins into distinct cellular organelles for functioning and survival. Highly specific sorting mechanisms to identify and distribute the polypeptides of the various cellular organelles to their correct destinations must exist.

Our research focuses on three areas, our goal being to understand the proteins that are present in regulated cellular compartments and to elucidate the mechanisms by which proteins are targeted to these organelles and subsequently trafficked to and from the plasma membrane.

• Zymogen Granules in the Exocrine Pancreas: we have discovered and characterized novel proteins in the membranes of secretory granules. Using both in vitro model systems and mouse models, including knockout mice, we study their importance in regulating the exocytosis of secretory granules containing digestive enzymes and also in protecting the pancreas from pancreatitis.

• Potassium Channels in Cardiac Myocytes: adenosine triphosphate–regulated potassium channels are vitally important for protecting the heart from ischemic events (heart attacks). We discovered that these channels in heart muscle cells are present in part within endosomal intracellular compartments and can be recruited to the cell surface in response to stress. We study the mechanisms by which these channels are trafficked back and forth from endosomal compartments to the cell surface.