Dr. Arvan's central focus is to examine molecular and cellular mechanisms involved in the selective targeting of newly-synthesized secretory proteins, using endocrine secretory proteins as a primary model. Current projects concentrate on: (1) the polarized trafficking of thyroglobulin (Tg) and thyroid peroxidase (TPO) through the secretory pathway for hormone synthesis in thyroid epithelial cells, (2) proinsulin trafficking to secretory granules for storage of insulin in the mature secretory granules of pancreatic b-cells, and 3) insulin trafficking in the yeast, S. cerevisiae. In all of these cell types, the lab is particularly interested in protein-protein associations taking place within the lumen of the secretory pathway that are required for maturation and proper intracellular transport of the prohormone/hormone.