Skip to content
Nobel Jews
Portrait of Martin Rodbell
Photo: Unknown author, http://profiles.nlm.nih.gov/GG/A/A/A/A/ Periodical: Environmental Health Perspectives, (November 1994): Cover. Photographic Print. Portrait. 1 Image. · Public domain via Wikimedia Commons

Nobel Prize in Physiology or Medicine · 1994

Martin Rodbell

He found that cells pass outside messages inward through a GTP-powered switch, key to how hormones, senses and many drugs work.

The Nobel citation: “for their discovery of G-proteins and the role of these proteins in signal transduction in cells”
Born
December 1, 1925, Baltimore, MD, USA
Died
December 7, 1998, Chapel Hill, NC, USA
Shared with
Alfred G. Gilman
Affiliation at the time
National Institute of Environmental Health Sciences, USA

Medicine prize

1994

Shared with 1 other laureate.

Age that year

69years

Born in 1925.

Headline credited impact

$22–26billion in economic value

Cumulative global sales of drugs that act on G-protein-coupled receptors, 1990-2025 (a proxy for economic activity). How it was built

Sources cited

28

Fact-checked September 24, 2026.

  • The key clue came from an impure chemical: commercial ATP carried traces of GTP, which worked at concentrations hundreds to a thousand times lower.
  • He and biochemist Oscar Hechter worked out the three-part model of cell signalling in a Washington hotel bar. Rodbell recalled sketching it on the tablecloth.
  • His wife, Barbara Ledermann, survived the Holocaust in Amsterdam under a false name. Her younger sister Sanne, a friend of Anne Frank, appears in Anne's diary.
  • For five or six years, colleagues at conferences asked whether he was going to talk about GTP again. In 1994 it won him a share of the Nobel Prize.
  • He wrote poems for special occasions all his life, and his speech at the 1994 Nobel banquet was written in verse.

The breakthrough

Finding the GTP-driven 'transducer' that carries signals across the cell membrane

Hormones such as glucagon and adrenaline cannot enter the cells they control. They dock on the outside, yet within seconds something changes inside. In the 1950s and 1960s Earl Sutherland showed that a docked hormone makes an enzyme on the inner side of the membrane produce a 'second messenger' called cyclic AMP. But how did the message get across the membrane? Working first with fat cells and then with membranes from rat liver, Rodbell's team at the NIH found that several different hormones seemed to share one enzyme. In 1969 he proposed that the system has three parts: a discriminator (the receptor that recognises the hormone), an amplifier (the enzyme that makes cyclic AMP) and, between them, a transducer that links the two. Think of a doorbell: a button outside, a bell inside, and a relay in the wall that only works when it has a battery. In 1970 and 1971 his team found the battery. Glucagon could not switch on the enzyme unless a small molecule called GTP was present, and GTP had been sneaking into their experiments as an impurity in ATP. It worked at concentrations hundreds to a thousand times lower than ATP. A stable version of GTP, made in 1973, switched on the enzyme in every kind of membrane they tested. Rodbell later argued that separate GTP-binding proteins turn the enzyme up and down, now called Gs and Gi. Alfred Gilman's lab then purified the first of these G-proteins.[1],[3],[4],[9],[14]

“As a Jew, fighting Hitler was the highest priority.”
Martin Rodbell, From his Nobel autobiography, describing why he gladly left Johns Hopkins for the wartime Navy. The Navy sent him to the Pacific instead.[2]

What it meant for humanity

G-proteins are the relays behind a huge share of the body's signalling. Hormones, many brain chemicals, light striking the eye, odours in the nose and flavours on the tongue all act through receptors that pass their message on through G-proteins. Rodbell's three-part picture of receptor, GTP-driven transducer and amplifier gave biologists a map of this system. His former colleague Lutz Birnbaumer later wrote that those three abstract parts match what are now called G-protein-coupled receptors, G-proteins and effectors. The map helps explain disease. Cholera toxin locks one G-protein in its 'on' state, so the intestine loses salt and water, causing the dehydration that makes cholera deadly. Whooping cough toxin blocks other G-proteins. Overactive G-proteins turn up in some tumours and in McCune-Albright syndrome, a rare hormone disorder, and an underactive one disturbs calcium and bone. The same map underpins modern pharmacology. A 2017 count found 481 drugs, about 34% of those approved in the United States, acting on G-protein-coupled receptors; another estimate put the number near 700. These drugs made up about 27% of the global medicines market, with sales of roughly $890 billion from 2011 to 2015. Rodbell did not create these medicines, many of which were found before anyone knew G-proteins existed, and a 1996 profile noted that no disease had yet been conquered directly because of the discovery. His contribution was to explain how such signals reach inside the cell. Earlier, his 1964 method for isolating living fat cells let endocrinologists study hormones on single cells, and the paper became one of the most-cited in science.

  • Cholera toxin jams one G-protein in its 'on' state, which drains salt and water from the gut. The Nobel Assembly cited this in 1994 as a direct G-protein link to disease.[3],[5]
  • G-proteins carry the signals for sight, smell and taste as well as for many hormones and brain chemicals.[3],[5]
  • About 34% of FDA-approved drugs (481 in a 2017 count) act on G-protein-coupled receptors, which pass their signals on through G-proteins. Another estimate puts the total near 700 drugs, or 35%.[22],[23]
  • His colleague Lutz Birnbaumer wrote that Rodbell's discriminator, transducer and amplifier correspond to today's G-protein-coupled receptors, G-proteins and effectors.[16]
  • His 1964 paper on isolated fat cells, made with a collagenase method he found, became one of the most-cited scientific articles, according to the Institute for Scientific Information.[2],[10]
  • As scientific director of the National Institute of Environmental Health Sciences from 1985 to 1989, he recruited scientists to build up its basic research.[15],[17]

Impact in numbers

Rodbell's legacy is mainly knowledge. He showed that a hormone's message crosses the cell membrane in steps, with a GTP-powered switch in the middle, and his framing helped turn 'signal transduction' into a field of its own. That framework now helps explain how we see, smell and taste, how cholera and whooping cough toxins do their damage, and how about a third of approved drugs act. We make one small, low-confidence claim on the outcome shared with Robert Lefkowitz and Otto Loewi: cumulative world sales of drugs acting on G-protein-coupled receptors, about $4.4 to $5.2 trillion from 1990 to 2025. We credit Rodbell with 0.5%, about $22 to $26 billion, because many of these drugs were found without any knowledge of G-proteins and Alfred Gilman shares the discovery. Sales measure spending, not health gained. We make no lives-saved claim, since no study separates his part. His fat-cell method and his years building basic research at NIEHS also go uncounted.

HealthFundamental scienceEconomy

Each number is the laureate’s credited share of a real-world outcome, cumulative to 2025. The whole outcome, the share of credit, and the reasoning are shown so you can check the arithmetic. Outcomes shared with other laureates are counted once on the impact page.

  • Low confidenceRippleModeledEconomy

    Cumulative global sales of drugs that act on G-protein-coupled receptors, 1990-2025 (a proxy for economic activity)

    $22–26

    billion in economic value, credited share

    That is 0.5% of $4.4–5.2 trillion in economic value since 1990.

    How this number was built

    Range reused from the Lefkowitz and Loewi profiles so totals line up. Low: 27% market share (Hauser 2017) of IMS prescription sales of $127.7B (1990) and $282.5B (2000) (WHO 2004, Table 4.2): 11 yrs x $55.4B avg = $0.61T; 2001-10 = 10 x avg($76.3B, $178B) = $1.27T; 2011-15 = $0.89T (Hauser); 2016-25 flat at $160B = $1.60T; total $4.37T. High: 35% (Sriram & Insel) gives $0.79T + $1.38T + $0.89T + ($178B growing 3%/yr) $2.10T = $5.16T. Nominal. Share: these drugs act by changing how a receptor switches on its G-protein, the GTP-driven transducer Rodbell proposed and demonstrated, but many GPCR drug classes were found before G-proteins were known. We give the G-protein discovery 1% of the outcome, split equally with co-laureate Gilman, who purified the protein: 0.005 ($22B-$26B). Sales measure spending, not benefit.[3],[22],[23],[24]

    Sources: Nature Reviews Drug Discovery (via PubMed Central); Molecular Pharmacology (via PubMed Central); World Health Organization; NobelPrize.org (Nobel Assembly at Karolinska Institutet)

The double edge

We found no weapons, deliberate harms or personal scandals tied to Rodbell or his discovery. The disputes are scientific. His later 'disaggregation' theory held that G-proteins sit in large clusters that break apart when a hormone arrives. It fell out of favour after other labs showed that activated G-proteins split into separate subunits, which Rodbell acknowledged in his Nobel lecture while still arguing that the clusters were real. The prize, limited to two people, also simplified a team effort. Rodbell himself called Lutz Birnbaumer a prime source of the findings behind the transducer idea and credited Cassel and Selinger with showing that breaking down GTP switches the signal off. Finally, the medical payoff has come more slowly than the science: in 1996 a profile noted that no disease had yet been defeated directly because of the G-protein discoveries.

  • Minor

    A later theory that did not hold up

    Rodbell's 'disaggregation theory' proposed that hormones break large clusters of G-proteins into single units. It lost favour when other labs showed that activated G-proteins instead split into an alpha subunit and a beta-gamma pair. In his Nobel lecture he accepted that the original theory needed changing but continued to argue that G-proteins form clusters in the membrane.[4]

  • Minor

    A two-person prize for a team discovery

    The GTP findings came from a lab team that included Lutz Birnbaumer, Stephen Pohl, Michiel Krans and Yoram Salomon, and other groups filled in key steps. Rodbell's own Nobel writings call Birnbaumer a prime source of the findings behind the transducer concept, and his Nobel lecture credits Cassel and Selinger with showing that breaking down GTP is the 'turn-off' step.[2],[4],[16]

  • Minor

    Slow route from discovery to cures

    A 1996 University of Washington profile observed that no disease had yet been defeated or cancer cured because of the discoveries of Rodbell and Gilman, though they had improved understanding of illnesses such as cholera.[14]

Against the odds

Rodbell grew up in a Jewish family above his father's small grocery in a blue-collar part of Baltimore; his parents had never been to college. He was not persecuted, but some doors were narrower for Jewish Americans. Johns Hopkins, which he entered in 1943, was led by Isaiah Bowman, who according to his biographer Neil Smith imposed a quota on Jewish students in 1942 and fired a young Jewish historian, saying there were already too many Jews at Hopkins. Medical schools screened applicants by religion: a 1946 review of 39 application forms found that all of them asked for it, and a 1945 magazine report put acceptance rates at 75% for Gentile applicants and 25% for Jews. Rodbell later recalled that medical school was especially hard to enter for Jews, and he turned from pre-medicine to research. As a Jewish teenager he wanted to fight Hitler; the Navy sent him to the Pacific as a radio operator with the Marines, where he caught malaria. The Holocaust reached his family through his wife. Barbara Ledermann survived in Amsterdam under a false identity, while her parents and younger sister were seized in a June 1943 raid and murdered at Auschwitz.

  • 1942

    Discrimination

    Isaiah Bowman, president of Johns Hopkins from 1935 to 1949, imposed a Jewish student quota in 1942 according to his biographer, and had fired a Jewish historian, saying Hopkins already had too many Jews. Rodbell studied there from 1943 to 1950; we found no record of the quota affecting him personally.[8],[20]

  • 1946

    Quota

    When Rodbell began pre-medical study after the war, medical school application forms routinely asked for religion, and Jewish applicants were admitted at far lower rates. He recalled that getting in was especially hard for Jews, and he chose research instead.[2],[12],[21]

  • 1944

    War

    Drafted into the Navy, he served as a radio operator attached to the Marines in the Pacific and caught malaria in the jungles of the Philippines.[2],[8],[12]

  • 1943

    Other

    His future wife's family was destroyed in the Holocaust. Barbara Ledermann's parents and younger sister were taken in a raid in Amsterdam on 20 June 1943 and murdered at Auschwitz; she survived under a false name and helped other Jews find hiding places.[2],[18],[19],[28]

Jewish background

Both parents JewishIdentified as Jewish, secular

Rodbell was born in Baltimore to Milton W. Rodbell, a grocery store owner, and Shirley Abrams Rodbell. Both parents are buried in the United Hebrew Cemetery near Baltimore, his mother in the plot of the Anshe Emunah Aitz Chaim congregation. He described himself as Jewish: his Nobel autobiography says that as a Jew he saw fighting Hitler as the highest priority, and in 1996 he recalled that medical school was especially hard to enter for Jews. In 1950 he married Barbara Ledermann, a German-born Jewish refugee who survived the Holocaust in Amsterdam. We found no source describing his religious practice.[2],[8],[12],[19],[25],[26]

Key dates

  1. December 1, 1925

    Born in Baltimore, Maryland, to Milton Rodbell, a grocer, and Shirley Abrams Rodbell. The family lives above the store.[1],[8],[12]

  2. 1943

    Enters Johns Hopkins University, where he is drawn to biology and to French literature.[2],[8]

  3. 1944

    Leaves Hopkins for Navy service as a radio operator; attached to the Marines, he catches malaria in the Philippines.[2],[8]

  4. 1949

    Earns a BS in biology from Johns Hopkins, then spends a year taking every advanced chemistry course available.[2],[8]

  5. 1950

    Marries Barbara Ledermann, a Holocaust survivor from Amsterdam, and moves to Seattle for graduate school.[8],[13],[19]

  6. 1954

    Completes a PhD in biochemistry at the University of Washington on how the liver makes lecithin, a membrane fat.[2],[8]

  7. 1956

    Joins the National Institutes of Health in Bethesda, starting a research career there that lasts 38 years.[7],[8]

  8. 1964

    Publishes 'The Metabolism of Isolated Fat Cells', a method that becomes one of the most-cited papers in science.[10]

  9. 1969

    Proposes that hormone signals pass through a discriminator, a transducer and an amplifier, and applies the term 'signal transduction' to biology.[4],[8],[9]

  10. 1971

    Publishes five papers showing that GTP is needed for glucagon to act on liver membranes, the discovery at the heart of his Nobel Prize.[8],[9],[14]

  11. 1985

    Becomes scientific director of the National Institute of Environmental Health Sciences in North Carolina, serving until 1989.[7],[17]

  12. October 10, 1994

    Months after retiring, shares the Nobel Prize in Physiology or Medicine with Alfred Gilman for the discovery of G-proteins.[1],[3],[15],[27]

  13. December 10, 1994

    Gives his Nobel banquet speech in the form of a poem he wrote for the occasion.[6],[11]

  14. December 7, 1998

    Dies in Chapel Hill, North Carolina, six days after his 73rd birthday, weeks after giving the first lecture in a series named for him.[1],[7]

Sources

  1. 1.Martin Rodbell - Facts · NobelPrize.org (Nobel Prize Outreach)
  2. 2.Martin Rodbell - Biographical (from Les Prix Nobel, The Nobel Prizes 1994) · NobelPrize.org (Nobel Foundation), 1995
  3. 3.Press release: The Nobel Prize in Physiology or Medicine 1994 · NobelPrize.org (Nobel Assembly at Karolinska Institutet), 1994
  4. 4.Signal Transduction: Evolution of an Idea (Nobel Lecture, 8 December 1994) · NobelPrize.org, 1994
  5. 5.Award ceremony speech by Bertil B. Fredholm, 1994 · NobelPrize.org, 1994
  6. 6.Martin Rodbell - Banquet speech, 10 December 1994 · NobelPrize.org, 1994
  7. 7.Biographical Overview (Martin Rodbell Papers, Profiles in Science) · US National Library of Medicine
  8. 8.Brief Chronology (Martin Rodbell Papers, Profiles in Science) · US National Library of Medicine
  9. 9.Signal Transduction and the Discovery of G-Proteins, 1969-1980 (Martin Rodbell Papers, Profiles in Science) · US National Library of Medicine
  10. 10.Early Work in Cellular Metabolism, 1956-1969 (Martin Rodbell Papers, Profiles in Science) · US National Library of Medicine
  11. 11.The Nobel Prize and Other Awards (Martin Rodbell Papers, Profiles in Science) · US National Library of Medicine
  12. 12.The 'G' Man: From Grocery Delivery Boy to the U-Dub (Tom Griffin), Columns, June 1996 · University of Washington Alumni Association, 1996
  13. 13.The 'G' Man: The UW Years - In the Lab and on the Stage (Tom Griffin), Columns, June 1996 · University of Washington Alumni Association, 1996
  14. 14.The 'G' Man: The Breakthrough that Led to the Prize (Tom Griffin), Columns, June 1996 · University of Washington Alumni Association, 1996
  15. 15.The 'G' Man: Later Years and the Day of the Award (Tom Griffin), Columns, June 1996 · University of Washington Alumni Association, 1996
  16. 16.The discovery of signal transduction by G proteins: a personal account and an overview of the initial findings (Lutz Birnbaumer, Biochim Biophys Acta 1768:756-771), author manuscript · Biochimica et Biophysica Acta (via PubMed Central), 2007
  17. 17.Martin Rodbell obituary (Environ Health Perspect 107(1):A9) · Environmental Health Perspectives / NIEHS (via PubMed Central), 1999
  18. 18.Barbara Ledermann (Knowledge base) · Anne Frank House
  19. 19.Oral history interview with Barbara Ledermann Rodbell (RG-50.030.0192), catalog record · United States Holocaust Memorial Museum, 1990
  20. 20.The man who redrew the world (Blanche Wiesen Cook, review of Neil Smith's 'American Empire') · Los Angeles Times, 2004
  21. 21.The Jewish Problem in U.S. Medical Education, 1920-1955 (Edward C. Halperin, Journal of the History of Medicine 56) · Journal of the History of Medicine and Allied Sciences (via Jewish Historical Society of South Carolina), 2001
  22. 22.Trends in GPCR drug discovery: new agents, targets and indications (Hauser AS et al., Nat Rev Drug Discov 16:829-842), author manuscript · Nature Reviews Drug Discovery (via PubMed Central), 2017
  23. 23.G protein-coupled receptors as targets for approved drugs: how many targets and how many drugs? (Sriram K, Insel PA, Mol Pharmacol 93:251-258) · Molecular Pharmacology (via PubMed Central), 2018
  24. 24.The World Medicines Situation (WHO/EDM/PAR/2004.5), Table 4.2 · World Health Organization, 2004
  25. 25.Milton William Rodbell (1902-1961), memorial with obituary notice, United Hebrew Cemetery, Halethorpe, Maryland · Find a Grave
  26. 26.Shirley Abrams Rodbell (1904-1982), memorial with obituary notice, United Hebrew Cemetery, Halethorpe, Maryland · Find a Grave
  27. 27.The 'G' Man: Fate, Fortitude and Frustration Were Part of the Path to a Nobel Prize (Tom Griffin), Columns, June 1996 · University of Washington Alumni Association, 1996
  28. 28.Susanne Ledermann (Knowledge base) · Anne Frank House

Fact-checked on September 24, 2026 by a separate AI fact-checking pass that re-opened the sources, with 6 corrections made. How we check

Suggest a correction