Summary: Danny Reinberg studies the regulation of gene expression in eukaryotes.Gene expression – the process that cells use to produce proteins from genes on DNA strands – is fundamental to all life. DNA sequences in genes are first “transcribed” to RNA molecules, which then become the templates for proteins. But this process must be controlled so that correct amounts and types of proteins are made in a normal cell. Moreover, in multicellular animals, the complex regulation of gene expression that results in different tissues during development and maintains tissue identity in the adult must be established.
In any tissue of the body, there are some genes that are never expressed – they are “silent” genes – and there are some genes that are expressed exclusively to this tissue, giving rise to its particular functions and identity. Somehow, when a cell in one organ divides, the identity of the organ is transmitted accurately to the daughter cells that now also exhibit this differential gene expression. How does this happen? This transmission of identity is not through the genes themselves, as all cell types contain the identical genetic makeup. Instead, this complex and fascinating process is functionally dependent on the proteins that structure the body of DNA. My laboratory’s long-term goal is to determine how a gene gets transcribed when it does, and what controls this process. To do this, we set out to determine the criteria that enable or disable transcription as a function of increasingly complex gene organization.
A Biochemist by Nature
by Karen Hopkin
Danny Reinberg has broken down everything from transcription factors to chromatin. Then he builds them back up, and the discoveries come.Danny Reinberg is a biochemist—a hard-core, purebred, columns-in-the-cold-room kind of biochemist. Born in Santiago, Chile, in 1954, Reinberg took his first biochemistry course as an undergraduate at the Catholic University in nearby Valparaiso. “I liked it so much that even though I got an A-minus, I went back and said, ‘You know, I don’t think I have a complete understanding and grasp of biochemistry. I’d like to take the course again.’” The professor, says Reinberg, “looked at me and said, ‘You’re crazy! Nobody wants to take it again.’” Although his grade actually went down the second time around, Reinberg says, “I loved it.”
That same passion for all things biochemical—and for protein purification in particular—has served Reinberg well. Now a Howard Hughes Medical Institute investigator at the New York University School of Medicine, Reinberg made a name for himself in the field of transcription by isolating the “factors that get together to form the monstrous apparatus that transcribes protein-coding genes,” says Rick Young of the Whitehead Institute. “Because of the sheer number and complexity of these components, purifying them and characterizing their activities was a biochemical tour de force.” Reinberg has since applied that same level of rigor, says Young, “to characterizing the factors that modify chromatin in the vicinity of the transcription apparatus and thereby contribute to gene regulation.”“I think Danny is one of the best people working in the chromatin/transcription field—and it’s a pretty big field with a lot of very good people,” adds Bob Tjian of the University of California, Berkeley. “He’s just a really good protein biochemist who knows how to purify proteins. That was—and is—a big advantage if you want to get down to the mechanistic aspects of complicated reactions and complex molecular machinery.”