Marilene Demasi1, Fernanda Marques da Cunha2. 1. Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, SP, Brazil. Electronic address: marilene.demasi@butantan.gov.br. 2. Departamento de Bioquímica, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil. Electronic address: fmcunha@unifesp.br.
Abstract
BACKGROUND: It has been almost three decades since the removal of oxidized proteins by the free 20S catalytic unit of the proteasome (20SPT) was proposed. Since then, experimental evidence suggesting a physiological role of proteolysis mediated by the free 20SPT has being gathered. SCOPE OF REVIEW: Experimental data that favors the hypothesis of free 20SPT as playing a role in proteolysis are critically reviewed. MAJOR CONCLUSIONS: Protein degradation by the proteasome may proceed through multiple proteasome complexes with different requirements though the unequivocal role of the free 20SPT in cellular proteolysis towards native or oxidized proteins remains to be demonstrated. GENERAL SIGNIFICANCE: The biological significance of proteolysis mediated by the free 20SPT has been elusive since its discovery. The present review critically analyzes the available experimental data supporting the proteolytic role of the free or single capped 20SPT.
BACKGROUND: It has been almost three decades since the removal of oxidized proteins by the free 20S catalytic unit of the proteasome (20SPT) was proposed. Since then, experimental evidence suggesting a physiological role of proteolysis mediated by the free 20SPT has being gathered. SCOPE OF REVIEW: Experimental data that favors the hypothesis of free 20SPT as playing a role in proteolysis are critically reviewed. MAJOR CONCLUSIONS: Protein degradation by the proteasome may proceed through multiple proteasome complexes with different requirements though the unequivocal role of the free 20SPT in cellular proteolysis towards native or oxidized proteins remains to be demonstrated. GENERAL SIGNIFICANCE: The biological significance of proteolysis mediated by the free 20SPT has been elusive since its discovery. The present review critically analyzes the available experimental data supporting the proteolytic role of the free or single capped 20SPT.