Controlled degradation of the proteins is involved in the regulation of many important cellular processes , including cell cycle , differentiation , management and distribution of protein , and programmed cell death. For several years, it is known that the degradation of specific proteins is also a very important part of the mechanisms governing the biogenesis of chloroplasts and their adaptations to changing environmental conditions and that the protease responsible for the digestion of proteins are localized in the chloroplast chloroplasts themselves .