Alteration of the quaternary structure of cpn60 modulates chaperonin-assisted folding. Implications for the mechanism of chaperonin action.

Mendoza, Jose A.; Demeler, Borries; Horowitz, Paul M.

doi:10.1016/s0021-9258(17)41966-1

Cited by 63 publications

(28 citation statements)

References 30 publications

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“…The successful refolding of GroES also has implications for the refolding of GroEL. Until very recently, it has been difficult to refold urea denatured GroEL (Price et al, 1993;Mendoza et al, 1994;Lissin et al, 1990;Ybarra & Horowitz, 1995). Previous studies have demonstrated that GroEL that had been disassembled in 4 M urea could reassemble in the presence of MgATP (Lissin et al, 1990).…”

Section: Discussionmentioning

confidence: 99%

“…Lissin and co-workers showed that GroEL can facilitate its own self-assembly in an ATP dependent fashion (Lissin et al, 1990;Lissin, 1995). Recent results in this lab have shown that structured, monomeric GroEL can be reassembled into a functional tetradecamer without the requirement of preassembled GroEL from a folded, monomeric state (Mendoza et al, 1994) or from a urea-denatured state in the presence of stabilizing agents (Ybarra & Horowitz, 1995).…”

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confidence: 99%

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Reversible Oligomerization and Denaturation of the Chaperonin GroES

et al. 1996

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The chaperonin GroEL can assist protein folding and normally acts with the co-chaperonin GroES. These Escherichia coli proteins are encoded on the same operon, with GroES positioned first. In this report, we have investigated the reversible folding of GroES. Using fluorescence anisotropy of dansyl-labeled GroES, intrinsic fluorescence, bis-ANS binding, sedimentation velocity, and limited proteolysis, we show that GroES unfolds in a single, two-state transition. Importantly, intrinsic fluorescence and sedimentation velocity analyses show that GroES is capable of refolding and reassembling from a urea denatured state. The refolded GroES is fully active as shown by its ability to assist GroEL in the refolding of rhodanese. These results indicate that chaperonins may not require other chaperonins for successful folding/assembly. We also show that GroES is capable of assisting in the refolding/reassembly of fully denatured GroEL. The reversible folding of GroES coupled with the ability of GroES to assist the refolding/reassembly of GroEL suggest that the groE operon may be organized in a manner that provides a structural role in GroES/GroEL assembly as well as a functional role.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Reversible Oligomerization and Denaturation of the Chaperonin GroES

et al. 1996

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“…Photoincorporation of Bis-ANS into GroEL in the Presence of Unfolded Rhodanese. Unfolded rhodanese was prepared in 8.0 M urea as described previously (Mendoza et al, 1994). GroEL was labeled under the conditions described above with the addition of differing amounts of unfolded rhodanese (see Figure 7 legend).…”

Section: Methodsmentioning

confidence: 99%

Photoincorporation of 4,4'-Bis(1-anilino-8-naphthalenesulfonic Acid) into the Apical Domain of GroEL: Specific Information from a Nonspecific Probe

Seale¹,

Martinez²,

Horowitz³

1995

Biochemistry

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The use of noncovalent hydrophobic probes such as bis-ANS has become increasingly popular in gaining structural information about protein structure and conformation. While these probes have provided rich information about protein conformation, specific information has been limited. In this report, we extend the usefulness of the probe bis-ANS by showing that it can be covalently photoincorporated into various proteins. Using the chaperonin GroEL, we have shown that it is possible to locate important hydrophobic surfaces through photoincorporation and peptide sequencing. It has been proposed that hydrophobic surfaces on the chaperonin may be responsible for the binding of unfolded polypeptides. We show here that photoincorporation of bis-ANS is able to locate a distinct hydrophobic surface on GroEL. Incorporation of the bis-ANS occurs within a 45 residue fragment of the monomer near the middle of the primary sequence. Interestingly, photoincorporation occurs within this fragment in both tetradecamers and assembly-competent monomers. From the three-dimensional structure of GroEL, this region maps to the apical domain (residues 191-376), which has been implicated in polypeptide binding [Fenton, W. A., Kashi, Y., Furtak, K., & Horwich, A. L. (1994) Nature 371, 614-619]. In addition, the fluorescent properties of the probe are retained including the excitation and emission maxima and the sensitivity to the polarity of its environment. These results suggest that photoincorporated bis-ANS may be a useful probe for protein structure and dynamics.

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“…It has been well-documented that the van Holde and Weischet analysis provides a rigorous test of sample homogeneity (Figure 2; van Holde & Weischet, 1978; Hansen et al, 1989;Gill et al, 1991;Geiselman et al, 1992;Hansen & Lohr, 1993). In addition, and at least of equal importance, it allows one to characterize complex multicomponent systems by sedimentation velocity analysis with confidence (Figure 2D-F; Hansen et al, 1989Hansen et al, , 1991Garcia-Ramirez et al, 1992;Hansen & Lohr, 1993;Hansen & Wolffe, 1994;Mendoza et al, 1994;Schwarz & Hansen, 1994;Behai et al, 1994;Musatov & Robinson, 1994).…”

Section: Sedimentation Velocity Methodsmentioning

confidence: 91%