Divergence and conservation of SUP2(SUP35) gene of yeasts Pichia pinus and Saccharomyces cerevisiae

Abstract

SUP2 (SUP35) is an omnipotent suppressor gene, coding for an EF-1 alpha-like protein factor, intimately involved in the control of translational accuracy in yeast Saccharomyces cerevisiae. In the present study a SUP2 gene analogue from yeast Pichia pinus was isolated by complementation of the temperature-sensitive sup2 mutation of S. cerevisiae. The nucleotide sequence of the SUP2 gene of P. pinus codes for a protein of 82.4 kDa, exceeding the Sup2 protein of S. cerevisiae by 6 kDa. Like the SUP2 gene product of S. cerevisiae, the Sup2 protein of P. pinus represents a fusion of a unique N-terminal part and a region homologous to EF-1 alpha. The comparison of amino acid sequences of the Sup2 proteins reveals high conservation (76%) of the C-terminal region and low conservation (36%) of the N-terminal part where, in addition, the homologous correspondence is ambiguous. Proteins related to the Sup2 of S. cerevisiae were found in P. pinus and some other yeast species by the immunoblotting technique. The relation between the evolutionary conservation of different regions of the Sup2 protein and their functional significance is discussed.

Yeast prions [URE3] and [PSI + ] are diseases

“…The prion domains of Ure2p and Sup35p are apparently dispensable for the functions of their respective proteins (51,52), and the conservation of these regions (20,23,53) has been invoked as an argument for the evolutionary importance of prion formation (17). However, deletion of the prion domain of Sup35p resulted in phenotypes that were frequently different from either being [psi Ϫ ] or [PSI ϩ ] under several different conditions (17), implying that the prion domain of Sup35p could have a function independent of prion formation.…”

The Role of the N-Terminal Oligopeptide Repeats of the Yeast Sup35 Prion Protein in Propagation and Transmission of Prion Variants

“…This plasmid was used to induce [PSI 1 ] appearance de novo. The centromeric URA3 plasmid pRS316-SUP35 carrying wild-type SUP35 and multicopy LEU2 plasmid pTR30-1 with SUP35 from Pichia methanolica were previously described (Kushnirov et al 1990). …”

HAM1, the gene controlling 6-N-hydroxylaminopurine sensitivity and mutagenesis in the yeast Saccharomyces cerevisiae

“…collection 'Segregate of diploid D365 from cross hml-l97/2d x XS122-57D (MATa ura3 rad52, Dr R. Mortimer). 'Segregate of the diploid D550 from a cross of 35G-D508 (MATa ura3 lys2-24 haml-1) and 33G-D373 (strain with high competence to lithium transformation, Kushnirov et al, 1990). 3Diploids D794 and D795 were obtained from cross of tl-CG379 (ham1::LEUZ) to DBU746 or t2-DBU746 (haml::LEU2), respectively.…”