Functional structure and physiological functions of mammalian wild-type HSP60

HSP60 possesses a GTPase activity and mediates protein folding with HSP10

“…1A ) to a Hill equation for two sequential allosteric transitions (Equation 1 in the materials and methods section), as did TRiC/CCT. Since we and others 16 , 18 found that HSP60 mainly exists in the heptameric single ring structure (Figure S1A ), we postulated that the first transition observed in ATPase activity corresponds to an intra-ring allosteric transition of single-ring HSP60. The oligomeric equilibrium of HSP60 was shifted from a single to double ring structure in the presence of ATP 18 .…”

“…It has been reported that mammalian HSP60, in contrast to GroEL, mainly exists as single heptameric ring 15 . X-ray crystallography demonstrated that HSP60 is converted to a tetradecameric double-ring structure in the presence of ATP, and HSP60 forms a football-type complex when both ATP and the co-chaperone, HSP10, are present 16 – 18 . Taken together, these studies strongly indicate that the ATP-dependent functional cycle of the HSP60/HSP10 complex is quite different from that of the bacterial GroEL/ES complex 19 .…”

“…We now report that the eukaryotic group I chaperonin HSP60 possesses GTPase activity and this reaction is regulated differently from the ATPase-dependent reaction. In comparison to the ATPase activity that produces the stable double-ring structure of HSP60 with HSP10, along with productive refolding of the denatured substrate proteins 16 – 18 , the GTPase activity of HSP60 was structurally and functionally quite different. These results demonstrate the importance of the ATPase-dependent cycle of HSP60 in protein folding and a supporting function for the GTPase activity.…”

Heat Shock Protein 60 in Hepatocellular Carcinoma: Insights and Perspectives

“…Importantly, HSPE1 (the homolog of bacterial GroES and known as HSP10) forms a single heptameric ring that functions as a cap for the HSPD1 assembly. This structural organization is essential for the ATP-dependent functionality of HSP60 in protein folding (Pace et al, 2013;Nisemblat et al, 2015;Okamoto et al, 2015). On the other hand, the cytosolic TRiC/CCT consists of eight subunits encoded by TCP1 and CCT2-8 genes and has its own built-in cap system (Leitner et al, 2012).…”

Genes diferencialmente expressos durante o desenvolvimento do ovário de abelhas <i>Apis mellifera</i>

“…O gene codificador do precursor mitocondrial Hsp60 também se mostrou mais expresso em ovários de rainhas, expressão possivelmente relacionada ao número maior de mitocôndrias nesta casta (Hartfelder et al, 2015). Adicionalmente ao seu papel como proteína de resposta a estresse, é responsável pelo enovelamento e transporte de proteínas do citoplasma para a matriz mitocondrial (Cheng;Hartl;Horwich, 1990;Okamoto et al, 2015).…”