Tag Archives: co-translational translocation



Quotation from Prof. David D. Sabatini (from 2005 Annual Review of Cell and Developmental Biology, volume 21, pages 1-33)
Quotation from Prof. David D. Sabatini (from 2005 Annual Review of Cell and Developmental Biology, volume 21, pages 1-33)


In this series, I am recommending to you a few life stories about real scientists.  I prefer to let these scientists tell their own stories where possible.  Autobiographical accounts are interesting and entertaining for both non-scientists and other scientists.  My selections here mostly involve scientists I either know personally or at least know about.  If further materials like this are needed, they can be obtained readily on the internet or with input from librarians at public or university libraries, science teachers, and other scientists.                                     

In the preceding segment of this series, the story of a very determined clinical research scientist working in Transplant Surgery and Immunology was recommended (see  http://dr-monsrs.net/2014/09/17/scientists-tell-us-about-their-life-and-work-part-6/ ).  Part 7 presents the activities of a very celebrated cell biologist whose research succeeded in untangling and explaining the extensive subcellular and molecular interactions occuring during the synthesis, trafficking, sorting, and secretion of proteins by our cells. 


David D. Sabatini has led modern research efforts to understand the very complex interactions taking place with the dynamics of proteins during their biosynthesis, co- and post-translational processing, sorting, and, secretion.  After receiving his M.D. degree in Argentina he came to the USA and earned a Ph.D. in 1966 at The Rockefeller University (New York).  His training and early research studies flourished at the very special research center established at Rockefeller by several founding fathers of cell biology (Profs. George Palade [1], Philip Siekevitz [2], and Keith R. Porter (see Part 2 in this series at:   http://dr-monsrs.net/2014/08/07/scientists-tell-us-about-their-life-and-work-part-2/ )).   Much of Sabatini’s reseach efforts have centered on ribosomes, the ribonucleoprotein assemblies that synthesize new proteins inside cells; his lab investigations led to breakthrough findings about the molecular mechanisms directing newly-synthesized proteins to their different intracellular or extracellular target destinations. 

Prof. Sabatini is especially renowned for co-discovering the signal hypothesis in collaboration with Prof. Günter Blobel (Rockefeller University).  This concept nicely explains the dramatic initial passage of all secreted proteins across the membrane (translocation) of endoplasmic reticulum via the presence of a short initial segment of aminoacids that is absent from non-secreted proteins retained for intracellular usage; this segment is termed ‘the signal for secretion’.  Subsequent research studies in other labs added to this hypothesis by discovering additional signals that directed different  newly synthsized proteins to other destinations inside cells;  the generalized signal hypothesis now explains much of the intracellular trafficking of proteins. 

By his nature, Prof. Sabatini always is intensely knowledgeable and enthusiastic about research questions and controversies in cell biology.  His numerous research publications always feature analysis of very detailed experimental results where data and interpretations are elegantly used to form groundbreaking conclusions.  Sabatini led the Department of Cell Biology at the New York University School of Medicine since 1972, and developed that into a leading academic center for modern teaching, scholarship, and research in cell and molecular biology.  He has served as the elected President of the Americal Society for Cell Biology (1978-79), and was awarded the E. B. Wilson Medal jointly with Prof. Blobel by that science society (1986).  In 2003, he received  France’s highest honor in science, the Grande Medaille d’Or (Grand Gold Medal).  Prof. Sabatini has merited membership in the USA National Academy of Sciences (1985), the American Philosophical Society, and the National Institute of Medicine (2000).   His celebrated research career exemplifies the important contributions that scientists from many other countries have made to USA science.   Prof. Sabatini recently retired, but his family name will continue to appear on many new research publications since several of his children have become very productive doctoral researchers in bioscience. 

[1]  Farquhar, M.G., 2012.  A man for all seasons: Reflections on the life and legacy of George Palade.  Annual Review of Cell and Developmental Biology28:1-28.  Available on the internet at:  http://www.annualreviews.org/doi/pdf/10.1146/annurev-cellbio-101011-155813

[2]  Sabatini, D. D., 2010.  Philip Siekevitz: Bridging biochemistry and cell biology.  The Journal of Cell Biology, 189:3-5.  Available on the internet at:  http://jcb.rupress.org/content/189/1/3.full.pdf . 

All 3 of my recommendations (below) provide exciting glimpses into real scientists in action. The first recommendation (1) is a short video presentation by Prof. Sabatini at the conclusion of the special Sabatini Symposium held in 2011 to honor him upon the occasion of retirement.  My second recommendation (2) is a superb autobiography giving many interesting stories about his life and career as a research scientist.  Non-scientist visitors are urged to read (only) pages 5-11; these present a fascinating account of his exciting adventures as a young scientist researching first with Barrnett at Yale University, and then with Palade and Siekevitz at The Rockefeller.  Doctoral scientists should read all of this very personal account.  The third selection (3) is a brief obituary he wrote about his teacher and mentor, Prof. Siekevitz; the stories told here illustrate the importance of scientists as people, and show that some of the controversial items discussed on Dr.M’s website also are of concern to other scientists.    

(1)    Sabatini, D. D., 2011.  Speech at awards ceremony and closing.  Sabatini Symposium, Dec. 2, 2011, New York University School of Medicine.  Available on the internet at:  http://sabatini.med.nyu.edu/videos/awards-ceremony-and-closing . 

(2)     Sabatini, D.D., 2005.  In awe of subcellular complexity: 50 years of trespassing boundaries within the cell.  Annual Review of Cell and Developmental Biology21:1-33.  Available on the internet at: 

 (3)     Sabatini, D. D., 2010.  Philip Siekevitz: Bridging biochemistry and cell biology.  The Journal of Cell Biology189:3-5.  Available on the internet at:  http://jcb.rupress.org/content/189/1/3.full.pdf



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