Joan Elaine Argetsinger Steitz (born January 26, 1941) is an American biochemist and molecular biologist, Sterling Professor of Molecular Biophysics and Biochemistry atYale University and Investigator at theHoward Hughes Medical Institute. She also serves as the Director of the Molecular Genetics Program at the Boyer Center for Molecular Medicine.[4] She is known for her discoveries involvingRNA, including insights into howribosomes interact withmessenger RNA by complementary base pairing and that introns are spliced bysmall nuclear ribonucleic proteins (snRNPs), which occur ineukaryotes.[5][6][7][8][9] In September 2018, Steitz won theLasker-Koshland Award for Special Achievement in Medical Science. The Lasker award is often referred to as the 'American Nobel' because 87 of the former recipients have gone on to win Nobel prizes.[10]
After completing her undergraduate degree, Steitz applied to medical school rather than graduate school since she knew of women medical doctors but not women scientists.[13] She was accepted to Harvard Medical School, but having been excited by a summer working as a bench scientist in the laboratory ofJoseph Gall at the University of Minnesota, she declined the invitation to Harvard Medical School and instead applied toHarvard's new program inbiochemistry and molecular biology. There, she was the first woman graduate student to join the laboratory of Nobel LaureateJames Watson, with whom she first worked onbacteriophageRNA.[14]
In 1970, Steitz joined the faculty atYale. In 1975, she published a research finding for which she is widely known, demonstrating that ribosomes usecomplementary base pairing to identify the start site on mRNA.[16][17]
In 1980, Steitz in collaboration with Michael Lerner published another critical paper, using immunoprecipitation with human antibodies from patients with autoimmunity to isolate and identifysnRNPs (pronounced "snurps") and detect their role insplicing.[5] A snRNP is a specific short length of RNA, around 150 nucleotides long, associated with protein, that is involved in splicing introns out of newly transcribed RNA (pre-mRNA), a component of thespliceosomes. Steitz's paper "set the field ahead by light years and heralded the avalanche of small RNAs that have since been discovered to play a role in multiple steps in RNA biosynthesis," notedSusan Berget.[13]
Steitz later discovered another kind of snRNP particle, thesnoRNP, involved in an important minority of mRNA splicing reactions. Via analysis of the genetic locations of the genes for snoRNPs, she demonstrated conclusively thatintrons are not "junk DNA" as they had often been described. Her work helps explain the phenomenon of "alternative RNA splicing."[18][19] Her discovery of the snRNPs and snoRNPs explains a mysterious finding: humans have only double the number of genes of a fruitfly. "The reason we can get away with so few genes is that when you have these bits of nonsense, you can splice them out in different ways," she said. "Sometimes you can get rid of things and add things because of this splicing process so that each gene has slightly different protein products that can do slightly different things. So it multiplies up the information content in each of our genes."[20]
In 1998 Steitz's research lab reported that the nuclear-cytoplasmic shuttling protein, HuR (ELAV-like protein1), could bind to theAU-rich element (ARE) in unstable mRNAs and increase their stability.[21] This work expanded the mechanistic understanding of the dual role that an ARE can play in posttranscriptional gene regulation.
Steitz has commented on the sexist treatment of women in science, and has been a "tireless promoter of women in science," noted Christine Guthrie, who described Steitz as "one of the greatest scientists of our generation."[13]
Steitz (born Joan Argetsinger) marriedThomas Steitz, also Sterling Professor of Molecular Biophysics and Biochemistry at Yale and the 2009Nobel Prize in Chemistry laureate, in 1966. They have one son, Jon.[24]
1976 – Eli Lilly Award in Biological Chemistry.[49]
1975 – Passano Foundation Young Scientist Award.[50]
Her nomination for the Royal Society reads:
Joan Steitz is one of the pioneers of the field of RNA biology who is world-renowned for her many seminal contributions. She showed howribosomal RNA is used to initiate translation at the start site of mRNA. She discoveredspliceosomes, the particles that are the sites of splicing of pre-messenger RNA into the final mature mRNA and elucidated many of their roles. She discovered that introns, which were thought to be inert, code forsno RNAs that target the modification of other cellular RNAs during their maturation. More recently she has found new roles formicroRNAs in gene regulation.[51]
^Thomas R. Cech and Joan A Steitz (2014) “The Noncoding RNA Revolution Trashing the Old Rules to Forge New Ones.”Cell157 (1): 77–94.
^Woan-Yuh Tam and Joan A. Steitz, (1997) “Pre-mRNA splicing: the discovery of a new spliceosome doubles the challenge. –Trends in Biochemical Sciences22(4): 132–37.
^Elaine Carey, "Female scientist 'a hero in her field': Yale's Joan Steitz, 65 honoured",Toronto Star April 3, 2006, p. A04; ("The Gairdner Foundation". Archived fromthe original on September 27, 2007. Retrieved2006-11-27.).
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