Inhibition of yeast ribosomal stalk phosphorylation by Cu–Zn superoxide dismutase

Relationship between the replicative age and cell volume in Saccharomyces cerevisiae.

“…The results of such comparisons (Table 1) demonstrate that the growth rate of the wild-type D1CSP4- 8C strain under conditions of division arrest remains controlled and is comparable to that of dividing cells, while cells of the DSCD1-1C strain seem to loose the control of the rate of protein synthesis in the shmoo state. This may be due to the fact that the Cu,Zn-SOD protein (SOD1) is an inhibitor of PK60S kinase controlling the translational activity of the ribosomes (Zielinski et al, 2002;Abramczyk et al, 2003), a function independent of the antioxidant action of this enzyme. The deficiency of this protein in the ∆sod1 mutant leads to the functioning of the translational system of the cell at a higher rate, and in consequence to an excessive increase in protein synthesis and cell size.…”

Molecular cloning of the ribosomal P-proteins MgP1, MgP2, MgP0, and superoxide dismutase (SOD) in the mussel Mytilus galloprovincialis and analysis of MgP0 at stress conditions

“…On the other hand, it is known that cells have the ability to metabolize the ROS with the antioxidant enzyme SOD (Arslantas, 2002), and they usually respond to cadmium or other heavy metals elevation with activation of antioxidant defense mechanisms, which protect them under such conditions (Viarengo et al, 1999). It has, also, been reported that in yeast, SOD acts as an inhibitor of casein kinase CK2, which phosprorylates P1/P2 proteins (Zielinski et al, 2002). In addition, SOD inhibits the catalytic subunit of casein kinase 2, CK2α′, previously known as PK60S (Abramczyk et al, 2003), which also phosphorylates P1/P2 proteins.…”

“…P1 and P2 proteins are found phosphorylated when bound to the ribosomes, at the last serine of the highly conserved C-terminal peptide, and reversible phosphorylation might participate in the control of ribosomal activity, regulating the number of active ribosomes (Zambrano et al, 1997;Zielinski et al, 2002). A cytoplasmic pool of non-phosphorylated proteins exists in the cells (SanchezMadrid et al, 1979), and an exchange process between proteins present on the ribosome and the cytoplasm takes place during protein synthesis, observed in yeast (Zinker and Warner, 1976), rat liver (Tsurugi and Ogata, 1985), and in plant cell cultures under stress conditions (Nover et al, 1986).…”

“…In yeast, the state of phosphorylation of P-proteins is regulated by direct interaction of superoxide dismutase (SOD) with protein kinase 60S (PK 60S), and a close correlation is found between the state of phosphorylation of Pproteins in diauxic shift and logarithmic growth cells and the activity of SOD (Zielinski et al, 2002). PK60S was identified as a catalytic subunit of casein kinase type 2 (CK2α′) (Abramczyk et al, 2003).…”

Different properties of four molecular forms of protein kinase CK2 from Saccharomyces cerevisiae.

“…The free CK2α' subunit was isolated according to the previously described procedure (Abramczyk et al, 2003). Protein kinase activities were tested under standard conditions with exogenous casein or bovine calmodulin, or with endogenous protein substrates (80S ribosomes, recombinant P2A and P2B) as previously described (Zieliński et al, 2002) using either [γ-32 P]ATP or [γ-32 P]GTP as a phosphate donor.…”