Dissociation and reconstitution of the <i>Thermoplasma</i> proteasome

Grziwa, Anja; Maack, Stephan; Pühler, Gabriela; Wiegand, Georg; Baumeister, Wolfgang; Jaenicke, Rainer

doi:10.1111/j.1432-1033.1994.tb19084.x

Cited by 22 publications

(12 citation statements)

References 14 publications

(9 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They most likely represent, respectively, the top view and side view of a particle consisting of a pair of interacting rings. These images are very similar to electron micrographs of the ␣-subunit of T. acidophilum (22,42). Detailed analysis of enlarged top and side views (Fig.…”

Section: Recombinant Hsc8 Protein Forms Large Complexes-hsc8supporting

confidence: 70%

The Human α-Type Proteasomal Subunit HsC8 Forms a Double Ringlike Structure, but Does Not Assemble into Proteasome-like Particles with the β-Type Subunits HsDelta or HsBPROS26

Gerards

Enzlin

Häner

et al. 1997

Journal of Biological Chemistry

View full text Add to dashboard Cite

The eukaryotic proteasome is a barrel-shaped protease complex made up of four seven-membered rings of which the outer and inner rings may contain up to seven different ␣-and ␤-type subunits, respectively. The assembly of the eukaryotic proteasome is not well understood. We cloned the cDNA for HsC8, which is one of the seven known human ␣-type subunits, and produced the protein in Escherichia coli. Recombinant HsC8 protein forms a complex of about 540 kDa consisting of double ringlike structures, each ring containing seven subunits. Such a structure has not earlier been reported for any eukaryotic proteasome subunit, but is similar to the complex formed by the recombinant ␣-subunit of the archaebacterium Thermoplasma acidophilum (Zwickl, P., Kleinz, J., and Baumeister, W. (1994) Nat. Struct. Biol. 1, 765-770). The ability of HsC8 to form ␣-rings suggests that these complexes may play an important role in the initiation of proteasome assembly in eukaryotes. To test this, we used two human ␤-type subunits, HsBPROS26 and HsDelta. Both these ␤-type subunits, either in the proprotein or in the mature form, exist in monomers up to tetramers. In contrast to the ␣-and ␤-subunit of T. acidophilum, coexpression of the human ␤-type subunits with HsC8 does not result in the formation of proteasome-like particles, which would be in agreement with the notion that proteasome assembly in eukaryotes is much more complex than in archaebacteria.

show abstract

Section: Recombinant Hsc8 Protein Forms Large Complexes-hsc8supporting

confidence: 70%

The Human α-Type Proteasomal Subunit HsC8 Forms a Double Ringlike Structure, but Does Not Assemble into Proteasome-like Particles with the β-Type Subunits HsDelta or HsBPROS26

Gerards

Enzlin

Häner

et al. 1997

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Such processing in trans can only be envisioned in a state where the subunits have not yielded their final fold within the complex or assuming a high conformational flexibility. The presence of the b-subunits' propeptide, which is comparably short in Thermoplasma (eight residues), is not required for assembly of proteasomes [46,47]. Similar to the above, in vitro assembly was observed with proteasomal a-and b-subunits of two other archaebacteria, Methanosarcina thermophila and Methanococcus jannaschii, indicating that no additional factors are essential for the assembly of these proteasomes [48,49].…”

Section: Assembly and Maturation Of Archaebacterial Proteasomessupporting

confidence: 62%

Ubiquitin-proteasome system

Heinemeyer

Ramos

Dohmen

2004

CMLS, Cell. Mol. Life Sci.

View full text Add to dashboard Cite

20S proteasomes constitute the proteolytic core of large protease complexes found in all branches of life. Among these, the eukaryotic 26S proteasome ubiquitously poses as a vital final entity in regulated degradation of intracellular proteins. The composition of 20S core particles has been disclosed in detail, facilitated by groundbreaking studies on ancestral prokaryotic 20S proteasomes of low complexity and culminated in the crystal structure determination of the much more complex eukaryotic particles. This article first summarizes insights into the structural organization of the 20S core followed by characterization of its proteolytic activities, which are confined to the central cavity of the particle. In eukaryotes they reside in three different subunit types differing in their preference for cleavage sites in substrates as well as in their importance for the proteasome's cellular function. The second part reviews current knowledge on the biogenesis pathways of 20S core particles, which have to ensure not only the fixed subunit arrangement but also activation of proteolytic subunits in a late assembly state.

show abstract

“…The reasons for this discrepancy are unclear but we note that proteasomes purified by the method of Dahlmann et al also differ from the ones purified by our procedure in other important properties, such as their dissociation and reconstitution [22].…”

Section: Specific Activities Of Selected Mutantscontrasting

confidence: 57%

The proteasome from Thermoplasma acidophilum is neither a cysteine nor a serine protease

et al. 1995

Self Cite

View full text Add to dashboard Cite

The 20 S proteasome, found in eukaryotes and in the archaebacterium Thermoplasma acldophilum, forms the proteolytic core of the 26 S proteasome which is the central protease of the non-lysosomal protein degradation pathway. Inhibitor studies have indicated that the 20 S proteasome may be an unusual type of cysteine or serine protease and a recent study of the Thermoplasma [3 subunit has indicated that it carries the proteolytic activity. We have attempted to obtain information on the nature of the active site by mutating the only cysteine, both histidines and two completely conserved aspartates in the archaebacterial complex as well as all serines of the/3 subunit, without decreasing the catalytic activity of the enzyme to any significant extent. Indeed, mutation of the conserved aspartate in the/3 subunit increased the activity of the proteasome threefold. We conclude that the proteasome is not a cysteine or serine protease.

show abstract

Dissociation and reconstitution of the Thermoplasma proteasome

Cited by 22 publications

References 14 publications

The Human α-Type Proteasomal Subunit HsC8 Forms a Double Ringlike Structure, but Does Not Assemble into Proteasome-like Particles with the β-Type Subunits HsDelta or HsBPROS26

The Human α-Type Proteasomal Subunit HsC8 Forms a Double Ringlike Structure, but Does Not Assemble into Proteasome-like Particles with the β-Type Subunits HsDelta or HsBPROS26

Ubiquitin-proteasome system

The proteasome from Thermoplasma acidophilum is neither a cysteine nor a serine protease

Contact Info

Product

Resources

About