Joan A Steitz PhD

Sterling Professor of Molecular Biophysics and Biochemistry; Investigator, Howard Hughes Medical Institute

Departments & Organizations

Yale Combined Program in the Biological and Biomedical Sciences (BBS): Biochemistry, Biophysics and Structural Biology

Office of Student ResearchStem Cell Center, Yale: Transcriptional Regulation of Stem and Progenitor CellsMolecular VirologyCenter for RNA Science and Medicine, YaleMolecular Biophysics and Biochemistry: RNA Biology; Steitz LabMolecular Virology


As a college student in the 1960s, Joan Steitz never imagined herself as a top-flight scientist. Certainly, she was fascinated by science. She even assisted senior scientists in laboratories at the Massachusetts Institute of Technology, where she was befriended by James D. Watson, co-discoverer of the DNA double helix, and at the Max Planck Institute in Germany. But when it came time to choose a career path, she had never seen a female professor or head of lab. So, she never aspired to such goals.

Today, Prof. Joan Steitz is one of leading scientists in her field. Steitz is best known for her pioneering work in RNA. She and her student Michael Lerner discovered and defined the function of small ribonucleoproteins (snRNPs) in pre-messenger RNA—the earliest product of DNA transcription—and was the first to learn that these cellular complexes (snRNPs) play a key role in processing messenger RNA by excising noncoding regions and splicing together the resulting segments. Her breakthroughs into the previously mysterious splicing process have clarified the science behind the formation of proteins and other biological processes, including the intricate changes that occur as the immune system and brain develop. Steitz earned her Ph.D. from Harvard in 1967. After completing postdoctoral work in Cambridge, England, she joined the Department of Molecular Biophysics and Biochemistry at Yale as an assistant professor and later became an associate and full professor, as well as chair of the department.


  • B.S., Antioch College , 1963
  • Ph.D., Harvard University , 1967

Selected Publication

  • Guo, Y.E., and Steitz, J.A. (2014). Virus meets host microRNA: the destroyer, the booster, the hijacker. Molec. Cell Biol. 34, 3780-3787.

Latest Honor and Recognition

  • The Passano Foundation Young Scientist Award(1975) , The Passano Foundation