David D. Sabatini

Sabatini is a native of Argentina, and attended medical school in Rosario at the National University of the Litoral. He began his research career at the University of Buenos Aires, in the laboratory of Eduardo de Robertis, a founder of modern cell biology, where he developed skills in electron microscopy. In 1961, as a Rockefeller Foundation fellow, he traveled to the United States, first for a six-month stint at Yale University to work with histochemist Russell Barnett, and then to work with George Palade and Philip Siekevitz at the Rockefeller University. Whilst at Yale he introduced glutaraldehyde as a fixative for electron microscopy and cytochemistry.Sabatini DD, Bensch K, Barrnett RJ. 1963. Cytochemistry and electron microscopy. The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation. J. Cell Biol. 17:19-58 After a year as a postdoctoral fellow at Rockefeller, Sabatini entered the Rockefeller graduate program from which he received a PhD in 1966 for studies on protein translation by ribosomes attached to endoplasmic reticulum membranes.Sabatini DD, Tashiro Y, Palade GE. 1966. On the attachment of ribosomes to microsomal membranes. J. Mol. Biol. 19:503-24; Redman CM, Sabatini DD. 1966. Vectorial discharge of peptides released by puromycin from attached ribosomes. Proc. Natl. Acad. Sci. USA 56:608-15Redman CM, Sabatini DD. 1966. Vectorial discharge of peptides released by puromycin from attached ribosomes. Proc. Natl. Acad. Sci. USA 56:608–15

Sabatini's research has focused on the mechanisms by which proteins are targeted to different organelles within the cell. His early work studied co-translational targeting of ribosomes to the endoplasmic reticulum and helped establish the hypothesis that signal peptides direct protein traffic to cellular compartments.Adesnik M. 2002. David Sabatini--a lifelong fascination with organelles. TRENDS in Cell Biology. 12:347-49 He later focused on trafficking from the Golgi apparatus to secretory vesicles and to the plasma membrane and in particular the mechanisms that address membrane proteins to the different surface domains of epithelial cells for which he employed viral infected epithelial monolayers.IN AWE OF SUBCELLULAR COMPLEXITY: 50 Years of Trespassing Boundaries Within the Cell David D. Sabatini Annual Review of Cell and Developmental Biology Vol. 21, 2005

After finishing his PhD, Sabatini joined the faculty at Rockefeller and in his own laboratory continued studies on protein trafficking in the ER. With a group of young associates (Nica Borgese, Mark Adelman, and Gert Kreibich), collaborating with Gunter Blobel, he continued research on the mechanism that ensures the co-translational translocation and vectorial discharge of nascent polypeptides into and across the endoplasmic reticulum membrane. In in vitro experiments they discovered that the microsomal membrane protected the N-terminal portion of nascent polypeptides synthesized in membrane bound ribosomes from proteolytic attack by exogenous enzymes.Sabatini, D.D. and Blobel (1970). Controlled proteolysis of nascent polypeptides in rat liver cell fractions. II. Location of the polypeptides in rough microsomes. J Cell Biol 45, 146-157.Blobel G. and Sabatini, D.D., (1970).Controlled proteolysis of nascent polypeptides in rat liver cell fractions.I. Location of the polypeptides within ribosomes. J Cell Biol 45, 130-145Adelman MR, Blobel G, Sabatini DD. 1973a. An improved cell fractionation procedure for the preparation of rat liver membrane-bound ribosomes. J. Cell Biol. 56:191–205Borgese N, Mok W, Kreibich G, Sabatini DD. 1974 Ribosomal-membrane interaction: in vitro binding of ribosomes to microsomal membranes. J Mol Biol. 25:559-80( These studies strongly implicated the N-terminal portions of nascent polypeptides in establishing and maintaining the association of bound ribosomes with ER membranes.

Largely based on these findings, in 1971 Blobel and Sabatini proposed a speculative modelG. Blobel, D.D. Sabatini,. Ribosome-membrane interaction in eukaryotic cells. 1971 Biomembranes, 2, 193–95 that later came to be known as the "signal hypothesis". For a discussion of the genesis and evolution of the signal hypothesis see LaBonte, 2017LaBonte, ML. 2017. Blobel and Sabatini's "Beautiful Idea": Visual Representations of the Conception and Refinement of the Signal Hypothesis. J Hist Biol. 2017 50(4):797-833 In the 1971 paper, Blobel and Sabatini proposed that “all mRNAs to be translated on bound ribosomes have a common feature, such as several codons near their 5’ end, not present in mRNAs which are to be translated on free ribosomes” and that “the resulting common sequence of amino acids near the N-termini of the nascent chains, or a modification of it, would then be recognized by a factor mediating the binding to the membrane." They proposed that "This binding factor could be a soluble protein, which recognizes both a site on the large ribosomal subunit and a site on the membrane.”G. Blobel, D.D. Sabatini,. Ribosome-membrane interactions in eukaryotic cells. 1971 Biomembranes, 2, 193–95 A decade later, Walter and Blobel demonstrated the existence of a Signal Recognition Protein (SRP) that mediates the binding of the ribosome and the signal sequence within the nascent chain to the membrane.Walter P. & Blobel G., 1981, Translocation of proteins across the endoplasmic reticulum II, Signal recognition protein(SRP) mediates the selective binding to microsomal membrane of in-vitro- assembled polysomes synthesizing secretory proteins. J. Cell Biol. 91:551-56Walter P. & Blobel G., 1983, Disassembly and reconstitution of signal recognition particle. Cell 54: 525-33 In 1982, a cognate receptor for the Signal Recognition Particle (SRP) was discovered and characterized in the ER membrane.Gilmore R. Blobel G. Walter P 1982a. Protein Translocation across the endoplasmic reticulum I. Detection in the microsomal membrane of a receptor for the signal recognition particle. J. Cell Biol. 95:463-69.Gilmore R. Walter P. Blobel G. 1982b Protein translocation across the endoplasmic reticulum II. Isolation and Characterization of the signal recognition particle receptor. J.Cell Biol. 95:470-77Meyer DI, Krause E, Dobberstein B.,1982). Secretory protein translocation across membranes—the role of the “docking protein” Nature 297:647-50

In 1972, Sabatini moved his laboratory to the New York University School of Medicine to become the chair of the Department of Cell Biology,{{cite journal|last1=Adesnik|first1=Milton|title=David Sabatini – a lifelong fascination with organelles|journal=Trends in Cell Biology|date=July 2002|volume=12|issue=7|pages=347–349|doi=10.1016/S0962-8924(02)02296-1|pmid=12185852}} where he assembled a group that focused on the study of membrane and organelle biogenesis.Adesnik M. 2002. David Sabatini – a lifelong fascination with organelles. TRENDS in Cell Biology. 12:347-49 Initially, that work placed a primary emphasis on identifying structural features of secretory, lysosomalRosenfeld MG, Krebich G, Popov D, Kato, K Sabatini DD 1982, Biosynthesis of lysosomal hydrolases: their synthesis in bound polysomes and the role of co- and post- translational processing in determining their subcellular substitution J. Cell Biol. 93:135-43) and integral membrane proteinsMonier, S, Van Luc P, Kreibich G, Sabatini DD, Adesnik M. (1988). Signals for the incorporation and orientation of Cytochrome P450 in the endoplasmic reticulum membranes. J Cell Biol. 107:457-70 that are synthesized on membrane bound ribosomes, address them to specific subcellular locations and determine their disposition within a membrane.

In the late 1970s, in collaboration with Marcelino CereijidoCereijido M, Robbins ES, Dolan WJ, Rotunno CA, Sabatini DD. 1978. Polarized monolayers formed by epithelial cells on a permeable and transculent support. J. Cell Biol. 77:853-80 he introduced the now widely used MDCK cell culture system for the study of epithelial cell polarity and together with Enrique Rodriguez-Boulan reported the landmark discovery of the asymmetric budding of specific enveloped viruses from the different surfaces of epithelial cells.Rodriguez-Boulan ER, Sabatini DD. 1978. Asymmetric budding of viruses in epithelial monolayers: a model system for study of epithelial polarity. Proc. Natl. Acad. Sci. USA 75:5071-75Coming to Grips with Cell Surface polarity. Simons K. 2017 Nat Rev Mol Cell Biol. 2017 18:278

Sabatini was elected a fellow of the American Academy of Arts and Sciences in 1980{{cite web|title=David Sabatini|url=https://www.amacad.org/content/system/search.aspx?s=david+sabatini|website=American Academy of Arts and Sciences|access-date=5 April 2017}}{{Dead link|date=January 2024 |bot=InternetArchiveBot |fix-attempted=yes }} and became a member of the U.S. National Academy of Sciences in 1985.{{cite web|title=David Sabatini|url=http://www.nasonline.org/member-directory/members/45760.html|website=National Academy of Sciences Member Directory|access-date=5 April 2017}} In 1986, together with Günter Blobel, he received the E.B. Wilson Medal, the highest honor of the American Society of Cell Biology, of which he was president in 1978-79.{{Cite web|url=http://www.ascb.org/about-ascb/past-ascb-officers/|title=Past ASCB Officers|website=American Society for Cell Biology|access-date=6 April 2017|archive-date=7 April 2017|archive-url=https://web.archive.org/web/20170407053610/http://www.ascb.org/about-ascb/past-ascb-officers/|url-status=dead}} He was selected to give the ASCB's Keith R. Porter Lecture in 1983.{{Cite web|url=http://www.ascb.org/keith-r-porter-lecture-award/|title=Keith R. Porter Lecture Award|website=American Society for Cell Biology|access-date=7 April 2017}}{{Cite web|url=http://www.ascb.org/e-b-wilson-medal/|title=E.B. Wilson Medal|website=American Society for Cell Biology|access-date=7 April 2017}}

He is a member of the U.S. National Academy of Medicine, a member of the American Philosophical Society,{{Cite web|title=APS Member History|url=https://search.amphilsoc.org/memhist/search?creator=David+D.+Sabatini&title=&subject=&subdiv=&mem=&year=&year-max=&dead=&keyword=&smode=advanced|access-date=2021-07-13|website=search.amphilsoc.org}} and a foreign associate of the French Academy of Sciences. He was awarded the Charles Leopold Mayer Prize (1986) and the Grande Médaille (2003) by the French Academy of Sciences, and in 2006 he was named a Chevalier de la Légion d’honneur.

Sabatini's wife Zulema is also from Argentina and is a medical doctor specializing in pathology. The couple's two sons are both current or former MD–PhD academic research scientists and Howard Hughes Medical Institute investigators: Bernardo L. Sabatini is a neuroscientist at Harvard Medical School and David M. Sabatini was a cell biologist at the Massachusetts Institute of Technology until he resigned in 2022.{{cite web|last1=Ware|first1=Lauren|title=Science in their Blood|url=http://www.hhmi.org/bulletin/spring-2013/science-their-blood|website=HHMI Bulletin|publisher=Howard Hughes Medical Institute|access-date=5 April 2017|date=2013}}{{cite web|last1=Wadman|first1=Meredith|title=Prominent biologist David Sabatini out at MIT after breaching sexual relationship policy|url=https://www.science.org/content/article/prominent-biologist-david-sabatini-out-mit-after-breaching-sexual-relationship-policy|website=ScienceInsider|publisher=American Association for the Advancement of Science|access-date=25 April 2022|date=2022}}{{cite web|last1=Weiss|first1=Suzy|title=He Was a World-Renowned Cancer Researcher.Now He's Collecting Unemployment.|url=https://www.commonsense.news/p/he-was-a-world-renowned-cancer-researcher|access-date=26 August 2022|date=2022}}

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Category:Cell biologists

Category:Rockefeller University alumni

Category:New York University faculty

Category:Fellows of the American Academy of Arts and Sciences

Category:Members of the United States National Academy of Sciences

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Category:Year of birth missing (living people)

Category:Fellows of the American Academy of Microbiology

Category:Members of the American Philosophical Society

Category:American biochemists

Category:Argentine biochemists

Category:Members of the National Academy of Medicine