Chaperonin-mediated folding in the eukaryotic cytosol proceeds through rounds of release of native and nonnative forms

Article Abstract:

Mediating ATP-dependent folding of actin and tubulin is significantly influenced by eukaryotic cytosolic chaperonin (CCT). Based on research, a newly synthesized substrate protein attaches to CCT in reticulocyte lysate or unaltered Xenopus oocytes. The production of the native state is strongly restrained when a chaperonin 'trap' is introduced. 'Trap' refers to the ability of the chaperonin to attach but not to be able to release substrate protein. On the other hand, when nonnative forms of actin, tubulin and G-transducin are detached from CCT, a small part attains native form with every round of release.

author: Farr, George W., Horwich, Arthur, Scharl, Elizabeth C., Schumacher, Robert J., Sondek, Stacey
Cell research, Cytological research, Cytosol

User Contributions:

Comment about this article or add new information about this topic:

CAPTCHA

The Hsp70 and Hsp60 chaperone machines

Article Abstract:

The Hsp70 and Hsp60 chaperones recognize hydrophobic surface in the context of extended and collapsed conformations bounded by local enclosure of the chain or by global enclosure of the polypeptide in a central cavity. These chaperones are characterized by a set of abundant cellular machines that aid in protein folding processes and binding to nonnative proteins associated with the bacterial cytoplasmic homolog. Substrates undergo several cycles of binding and release at a stoichiometry of a single Hsp70 monomer per substrate molecule.

author: Horwich, Arthur L., Bukau, Bernd
Proteins, Cell physiology

User Contributions:

Comment about this article or add new information about this topic:

CAPTCHA

Molecular chaperones and protein quality control

Article Abstract:

Elaborate quality control strategies have evolved to counter inevitable mishaps in living cells where newly made and preexisting polypeptide chains are at risk for misfolding and aggregation. Studies describe the removal of aggregates from the cytosol, reveal mechanisms for protein quality control in the endoplasmic reticulum and provide new insight into two classes of molecular chaperones, the Hsp70 system and the AAA+ (Hsp 100) unfoldases.

author: Bukau, Bernd, Horwich, Arthur, Weissman, Jonathan
Science & research, Endoplasmic reticulum, Genetic research, Molecular chaperones

User Contributions:

Comment about this article or add new information about this topic:

CAPTCHA


subjects list: Research, Analysis, Polypeptides
This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.