Home > Martin Rodbell
Martin Rodbell ( December 1, 1925- December 7, 1998) was an American biochemist and molecular endocrinologist who is best known for his discovery of G-proteins. He shared the 1994 Nobel Prize in Physiology or Medicine with Alfred G. Gilman for "their discovery of G-proteins and the role of these proteins in signal transduction in cells." 1 Research
Reflecting the increasingly common analogies between computer science and biology in the 1960s, Rodbell believed that the fundamental information processing systems of both computers and biological organisms were similar. He asserted that individual cells were analogous to cybernetic systems made up of three distinct molecular components: discriminators, transducers, and amplifiers (otherwise known as effectors). The discriminator, or cell receptor, receives information from outside the cell; a cell transducer processes this information across the cell membrane; and the amplifier intensifies these signals to initiate reactions within the cell or to transmit information to other cells.
In December 1969 and early January 1970, Rodbell was working with a laboratory team that studied the effect of the hormone glucagonGlucagon is a 29 amino acid polypeptide acting as an important hormone in carbohydrate metabolism. The polypeptide has a molecular weight of 3485 daltons and was discovered in 1923 by Kimball and Murlin. Its primary structure is: :NH-His-Ser-Gln-Gly-Thr-P on a rat liverThe liver is an organ in vertebrates including humans. It plays a major role in metabolism and has a number of functions in the body including detoxification, glycogen storage and plasma protein synthesis. It also produces bile which is important for dige membrane receptor--the cellular discriminator that receives outside signals. Rodbell discovered that ATP ( adenosine triphosphateFor other uses of the initials ATP, see ATP (disambiguation Adenosine triphosphate ATP is the nucleotide known in biochemistry as the " molecular currency" of intracellular energy transfer; that is, ATP is able to store and transport chemical energy withi) could reverse the binding action of glucagon to the cell receptor and thus dissociate the glucagon from the cell altogether. He then noted that traces of GTP ( guanosine triphosphate) could reverse the binding process almost one thousand times faster than ATP. Rodbell deduced that GTP was probably the active biological factor in dissociating glucagon from the cell's receptor, and that GTP had been present as an impurity in his earlier experiments with ATP. This GTP, he found, stimulated the activity in the guanine nucleotide protein (later called the G-protein), which, in turn, produced profound metabolic effects in the cell. This activation of the G-protein, Rodbell postulated, was the " second messengerIn biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay a signal within a cell. They are synthesized or released by specific enzymatic reactions, usually as a result of an external signal that was re" process that Earl W. Sutherland had theorized. In the language of signal transduction, the G-protein, activated by GTP, was the principal component of the transducer, which was the crucial link between the discriminator and the amplifier. Later, Rodbell postulated, and then provided evidence for, additional G-proteins at the cell receptor that could inhibit and activate transduction, often at the same time. In other words, cellular receptors were sophisticated enough to have several different processes going on simultaneously.
2 Biography
Rodbell was born in Baltimore, MarylandThis article is about the city in the US state of Maryland. For other meanings of the word "Baltimore", please see: Baltimore (disambiguation Baltimore is an independent city located in the U. State of Maryland. As of July 1, 2002, the population is 638,6. He entered Johns Hopkins UniversityThe Johns Hopkins University is a prestigious private institution of higher learning located in Baltimore, Maryland. Hopkins holds many "firsts" in American education: it was the first university in the United States to put an emphasis on research, founde in 1943, with interests in biology and French existential literature. In 1944, his studies were interupted by his military service as a U.S. Navy radio operator during World War II. He returned to Hopkins in 1946 and received his B.S. in biology in 1949. In 1950, he married Barbara Ledermann, with whom he had four children. Rodbell received his Ph.D. in biochemistry at the University of Washington in 1954. He did post-doctoral work at the University of Illinois at Urbana-Champaign from 1954 to 1956. In 1956, Rodbell accepted a position as a research biochemist at the National Heart Institute, part of the National Institutes of Health, in Bethesda, Maryland. In 1985, Rodbell became Scientific Director of the NIH's National Institute of Environmental Health Sciences in Chapel Hill, North Carolina where he worked until his retirement in 1994. He died in Chapel Hill of multiple organ failure after an extended illness.
This article contains text from the website of the NIH, part of the U.S. Government, and thus under public domain
