Disruption of tobacco chloroplast clpP gene encoding a proteolytic subunit of ATP-dependent protease

摘要

ATP-dependent Clp protease is highly conserved among divergent organisms and presents in chloroplasts and mitochondria in higher plants (Schirmer et al. 1996, Suzuki et al. 1997). Clp complex consists of two heptameric proteolytic subunits, which are flanked at one or both sides by hexameric rings of regulatory subunits. Regulatory subunit genes consist of small gene family, which makes it easier for the Clp complex to become involved in divergent cellular functions. In higher plants, proteolytic subunits are encoded both by the chloroplast clpP gene (clpP1) and the nuclear gene family (Adam et al. 2001). Proteolytic ring is a complex mixture of divergent subunits (Peltier et al. 2001). In microorganisms, Clp protease has two distinct physiological functions; (1) degradation of denatured or abnormal proteins, (2) specific proteolysis of regulatory proteins with short half-lives (Schirmer et al. 1996, Suzuki et al. 1997). To analyze the physiological function of Clp protease in chloroplasts, we disrupted tobacco clpP1.