Dithiothreitol triggers photooxidative stress and fragmentation of the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase in intact pea chloroplasts

Metabolic Regulation of Leaf Senescence in Sunflower (Helianthus annuus L.) Plants

“…Oxidized GS becomes more susceptible to proteolysis (Ortega et al, 1999); under photo-oxidative stress, GS2 cleavage occurs preferentially around the catalytic site (Ishida et al, 2002). Senescence may therefore have a direct impact on GS2 activity through enzyme degradation initiated by reactive oxygen species as reported in Rubisco (Ishida et al, 1997;Roulin & Feller, 1998).…”

Senescence in wheat leaves: is a cysteine endopeptidase involved in the degradation of the large subunit of Rubisco?

“…Moreover, it has been reported by Navarre and Wolpert (1999) that in victorin-treated leaf slices, the formation of the 53 kDa fragment could be prevented in a similar manner by the addition of two different cysteine protease inhibitors (E-64 and leupeptin). In intact chloroplasts and chloroplast lysates, the most prominent cleavage products of LSU had molecular weights of about 36 and 16-kDa, but no 50 kDa product was described (Desimone et al 1996;Ishida et al 1997;Roulin and Feller 1998b). Degradation products of about 50 kDa could be detected in lysates only if chloroplasts were contaminated with vacuolar proteases (Miyadai et al 1990).…”

“…A role for activated oxygen species in the degradation of Rubisco in intact chloroplasts seems likely. Both stimulation of Rubisco degradation under oxidative conditions (Desimone et al 1996;Roulin and Feller 1998b) and direct fragmentation of the enzyme by hydroxyl radicals (Ishida et al 1998) have been reported. The most prominent degradation product of LSU in chloroplasts or their lysates had a molecular mass in the range of 36-37 kDa (Desimone et al 1996;Ishida et al 1997;Roulin and Feller 1998b).…”

“…Both stimulation of Rubisco degradation under oxidative conditions (Desimone et al 1996;Roulin and Feller 1998b) and direct fragmentation of the enzyme by hydroxyl radicals (Ishida et al 1998) have been reported. The most prominent degradation product of LSU in chloroplasts or their lysates had a molecular mass in the range of 36-37 kDa (Desimone et al 1996;Ishida et al 1997;Roulin and Feller 1998b). This fragment likely contains the N-terminus of Rubisco (Ishida et al 1997(Ishida et al , 1998Roulin and Feller 1998b), although another fragment without the N-terminus of LSU was mentioned by Desimone et al (1996).…”

“…The most prominent degradation product of LSU in chloroplasts or their lysates had a molecular mass in the range of 36-37 kDa (Desimone et al 1996;Ishida et al 1997;Roulin and Feller 1998b). This fragment likely contains the N-terminus of Rubisco (Ishida et al 1997(Ishida et al , 1998Roulin and Feller 1998b), although another fragment without the N-terminus of LSU was mentioned by Desimone et al (1996). The direct cleavage of Rubisco in vitro by active oxygen species resulted in the formation of an N-terminal 37-kDa product and a 16-kDa fragment bearing the Cterminus (Ishida et al 1998(Ishida et al , 1999.…”