Mutational Effects on Inclusion Body Formation

Abstract

Publisher Summary Inclusion body formation has been studied most extensively in Escherichia coli ( E. coli) and Salmonella typhimurium , but the phenomenon is not isolated to prokaryotes. Inclusion bodies have been detected in eukaryotic cells, for example, in diseased human hepatocytes and inside algal chloroplasts. In bacteria, inclusion bodies have been observed to span the full width of a cell. The recognition of the nature of aggregation upon dilution from denaturant left open the question of the origin of inclusion bodies formed from newly synthesized proteins within cells. Intracellular protein deposits, such as Heinz bodies had been identified as associated with specific amino acid substitutions, but these findings from pathology were not initially recognized as protein misfolding. Investigation of the intracellular folding of the P22 tail spike provided direct evidence, that inclusion bodies were derived from the in vivo association of partially folded intermediates. Studies with interferon and interleukin expressed in E. coli confirmed that single amino acid substitutions could influence misfolding and aggregation pathways. This chapter reviews these efforts to isolate mutations affecting intracellular chain folding and other studies related to them.