Protein unfolding--an important process in vivo?
Protein unfolding is an important step in several cellular processes, most interestingly protein degradation by ATP-dependent proteases and protein translocation across some membranes. Unfolding can be catalyzed when the unfoldases change the unfolding pathway of substrate proteins by pulling at their polypeptide chains. The resistance of a protein to unraveling during these processes is not determined by the protein's stability against global unfolding, as measured by temperature or solvent denaturation in vitro. Instead, resistance to unfolding is determined by the local structure that the unfoldase encounters first as it follows the substrate's polypeptide chain from the targeting signal. As unfolding is a necessary step in protein degradation and translocation, the susceptibility to unfolding of substrate proteins contributes to the specificity of these important cellular processes.
Matouschek
Andreas
A
Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA. matouschek@northwestern.edu
D049069:ATP-Dependent Proteases; D002384:Catalysis; D064211:Connectin; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D009124:Muscle Proteins / Q000737:chemistry; D018482:Muscle, Skeletal / Q000737:chemistry / Q000502:physiology; D014176:Protein Biosynthesis; D011489:Protein Denaturation; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D012518:Sarcomeres / Q000737:chemistry / Q000502:physiology; D012697:Serine Endopeptidases / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity
D064211:Connectin; D006360:Heat-Shock Proteins; D009124:Muscle Proteins; D011498:Protein Precursors; D011506:Proteins; D011494:Protein Kinases; D049069:ATP-Dependent Proteases; D012697:Serine Endopeptidases