John Regan

G-protein coupled receptors (GPCR) are integral membrane proteins that transduce extracellular hormonal signals from the plasma membrane to the interior of the cell. This large family of receptors is related both structurally and functionally. Structurally, GPCRs share a characteristic "seven transmembrane motif" which means that there are seven regions of the receptor that cross the plasma membrane. Functionally, GPCRs share the ability to interact with so-called ‘G-proteins’ following stimulation of the receptor by a hormonal signal.

The G-proteins, or "guanine nucleotide binding regulatory proteins," lend their name to the GPCRs, but they actually represent a separate family of proteins. Upon stimulation of a GPCR by a hormonal signal one or more G-proteins are activated; which in turn activate additional families of proteins, which activate more proteins, etc. The end result of this is an increasing complex signaling cascade that culminates in a macroscopic response; e.g., muscle contraction, nerve depolarization, shape change, etc. The general interests of the Regan laboratory are to understand how drugs work by studying molecular biology and signal transduction mechanisms of the G-protein coupled receptors (GPCRs).

There are hundreds of different GPCRs; the ones under investigation in the Regan lab include the adrenergic and prostaglandin receptors that mediate the actions of adrenaline (epinephrine) and the prostaglandins, respectively. To study the GPCRs and their signal transduction pathways a variety of recombinant DNA approaches are utilized including the polymerase chain reaction (PCR), gene cloning, heterologous expression, and site-directed mutagenesis. In addition, functional approaches are employed such as the biochemical determination of second messenger function (e.g., protein phosphorylation, cAMP, calcium signaling) as well as immunofluorescence microscopy and real-time videomicroscopy. The goal of this work is to contribute to a better understanding of the GPCRs, their role in the biology of the cell, and their potential as targets for drug development. 

Honors & Awards
1996, Linköping University, Sweden M.D. honoris causa
1992, Syntex Prize in Receptor Pharmacology