Search PubMed⌕ Search

Biomedical subjects

Boris Magasanik

Publications and source records attributed to Boris Magasanik.

4 recordsLinked to original sources
PubMed2005

The transduction of the nitrogen regulation signal in Saccharomyces cerevisiae.

In cells of Saccharomyces cerevisiae, using ammonia as a source of nitrogen, Gln3p is sequestered in the cytoplasm by Ure2p but enters the nucleus when the cells are shifted to a nonpreferred source of nitrogen such as proline. The interpretation of recently published observations provides evidence for the view that Ure2p is the sensor for a drop in the intracellular concentration of glutamine, a signal that results in the polyubiquitination of the vesicle responsible for retaining the Gln3p-Ure2p complex in the cytoplasm. As a consequence of the drop in glutamine concentration, Gln3p is able to enter the nucleus and to activate the transcription of nitrogen-regulated genes.

Actins↗
PubMed2005

Origins.

Explore the source record for details and available documents.

Acetobacter↗
PubMed2002

Nitrogen regulation in Saccharomyces cerevisiae.

Yeast cells can respond to growth on relatively poor nitrogen sources by increasing expression of the enzymes for the synthesis of glutamate and glutamine and by increasing the activities of permeases responsible for the uptake of amino acids for use as a source of nitrogen. These general responses to the quality of nitrogen source in the growth medium are collectively termed nitrogen regulation. In this review, we discuss the historical foundations of the study of nitrogen regulation as well as the current understanding of the regulatory networks that underlie nitrogen regulation. One focus of the review is the array of four GATA type transcription factors which are responsible for the regulation the expression of nitrogen-regulated genes. They are the activators Gln3p and Nil1p and their antagonists Nil2p and Dal80p. Our discussion includes consideration of the DNA elements which are the targets of the transcription factors and of the regulated translocation of Gln3p and Nil1p from the cytoplasm to the nucleus. A second focus of the review is the nitrogen regulation of the general amino acid permease, Gap1p, and the proline permease, Put4p, by ubiquitin mediated intracellular protein sorting in the secretory and endosomal pathways.

Amino Acid Transport Systems↗