Wanderings in Biochemistry [Microbiology]

May 27th, 2014 by Lengyel, P.

My PhD thesis in the laboratory of Severo Ochoa at New York University School of Medicine in 1962 included the determination of the nucleotide compositions of codons specifying amino acids. The experiments were based on the use of random copolyribonucleotides - synthesized by polynucleotide phosphorylase - as messenger RNA in a cell-free protein synthesizing system. At Yale University, where I joined the faculty, my coworkers and I first studied the mechanisms of protein synthesis. Thereafter, we explored the interferons which were discovered as antiviral defense agents but were revealed to be components of a highly complex multifunctional system. We isolated pure interferons and characterized interferon-activated genes, the proteins they encode and their functions. We concentrated on a cluster of interferon-activated genes, the p200 cluster that arose by repeated gene duplications and encodes a large family of highly multifunctional proteins. For example, p204, a murine protein, can be activated in numerous tissues by distinct transcription factors. It modulates cell proliferation and the differentiation of a variety of tissues by binding to many proteins. p204 also inhibits the activities of wild-type Ras proteins and Ras oncoproteins.