Cell Regulation by Proteolytic Systems and Protein Conjugation
from: Halophiles: Genetics and Genomes (Edited by: R. Thane Papke and Aharon Oren). Caister Academic Press, U.K. (2014)
Proteases and protein conjugation systems are important in regulating cell function. Archaea synthesize (or are predicted to encode) numerous types of regulatory proteases including proteasomes, Lon protease, intramembrane cleaving proteases and others. Of these, proteasomes are demonstrated to be important in stress responses and essential to the growth of halophilic archaea. Halophilic archaea also synthesize a protein conjugation system termed sampylation in which different ubiquitin-like SAMPs are conjugated to protein targets through isopeptide bonds. While as yet unknown, sampylation is thought to regulate cellular functions by targeting proteins for proteasome-mediated degradation and for other non-proteolytic modifications. This chapter is focused on how archaea may regulate cell function through proteolysis and protein conjugation with emphasis on the halophilic archaea read more ...