NR ANMA
AU Komar,A.A.; Lesnik,T.; Cullin,C.; Merrick,W.C.; Trachsel,H.; Altmann,M.
TI Internal initiation drives the synthesis of Ure2 protein lacking the prion domain and affects [URE3] propagation in yeast cells
QU EMBO Journal 2003 Mar 3; 22(5): 1199-1209
PT journal article
AB The [URE3] phenotype in Saccharomyces cerevisiae is caused by the inactive, altered (prion) form of the Ure2 protein (Ure2p), a regulator of nitrogen catabolism. Ure2p has two functional domains: an N-terminal domain necessary and sufficient for prion propagation and a C-terminal domain responsible for nitrogen regulation. We show here that the mRNA encoding Ure2p possesses an IRES (internal ribosome entry site). Internal initiation leads to the synthesis of an N-terminally truncated active form of the protein (amino acids 94-354) lacking the prion-forming domain. Expression of the truncated Ure2p form (94-354) mediated by the IRES element cures yeast cells of the [URE3] phenotype. We assume that the balance between the full-length and truncated (94-354) Ure2p forms plays an important role in yeast cell physiology and differentiation.
AD Institut für Biochemie und Molekularbiologie, Universität Bern, Buehlstrasse 28, 3012 Bern, Switzerland, Institut de Biochimie et Genetique Cellulaires, 1 Rue Camille Saint-Saens, 33077 Bordeaux Cedex, France and Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH 44106-4935, USA Corresponding author e-mail: aak11@po.cwru.edu
SP englisch