| 1. |
- Kampinga, Harm H., et al.
(författare)
-
Function, evolution, and structure of J-domain proteins
- 2019
-
Ingår i: Cell stress & chaperones (Print). - : Springer Science and Business Media LLC. - 1355-8145 .- 1466-1268. ; 24:1, s. 7-15
-
Forskningsöversikt (refereegranskat)abstract
- Hsp70 chaperone systems are very versatile machines present in nearly all living organisms and in nearly all intracellular compartments. They function in many fundamental processes through their facilitation of protein (re)folding, trafficking, remodeling, disaggregation, and degradation. Hsp70 machines are regulated by co-chaperones. J-domain containing proteins (JDPs) are the largest family of Hsp70 co-chaperones and play a determining role functionally specifying and directing Hsp70 functions. Many features of JDPs are not understood; however, a number of JDP experts gathered at a recent CSSI-sponsored workshop in Gdansk (Poland) to discuss various aspects of J-domain protein function, evolution, and structure. In this report, we present the main findings and the consensus reached to help direct future developments in the field of Hsp70 research.
|
|
| 2. |
- Karamyshev, Andrey L., et al.
(författare)
-
Inefficient SRP Interaction with a Nascent Chain Triggers a mRNA Quality Control Pathway
- 2014
-
Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 156:1-2, s. 146-157
-
Tidskriftsartikel (refereegranskat)abstract
- Misfolded proteins are often cytotoxic, unless cellular systems prevent their accumulation. Data presented here uncover a mechanism by which defects in secretory proteins lead to a dramatic reduction in their mRNAs and protein expression. When mutant signal sequences fail to bind to the signal recognition particle (SRP) at the ribosome exit site, the nascent chain instead contacts Argonaute2 (Ago2), and the mutant mRNAs are specifically degraded. Severity of signal sequence mutations correlated with increased proximity of Ago2 to nascent chain and mRNA degradation. Ago2 knockdown inhibited degradation of the mutant mRNA, while overexpression of Ago2 or knockdown of SRP54 promoted degradation of secretory protein mRNA. The results reveal a previously unappreciated general mechanismof translational quality control, in which specific mRNA degradation preemptively regulates aberrant protein production (RAPP).
|
|
| 3. |
- Peisker, Kristin, et al.
(författare)
-
The ribosome-bound Hsp70 homolog Ssb of Saccharomyces cerevisiae
- 2010
-
Ingår i: Biochimica et Biophysica Acta. Molecular Cell Research. - : Elsevier BV. - 0167-4889 .- 1879-2596. ; 1803:6, s. 662-672
-
Forskningsöversikt (refereegranskat)abstract
- The Hsp70 homolog Ssb directly binds to the ribosome and contacts a variety of newly synthesized polypeptide chains as soon as they emerge from the ribosomal exit tunnel For this reason a general role of Ssb in the de novo folding of newly synthesized proteins is highly suggestive. However, for more than a decade client proteins which require Ssb for proper folding have remained elusive. It was therefore speculated that Ssb, despite its ability to Interact with a large variety of nascent polypeptides, may assist the folding of only a small and specific subset. Alternatively, It has been suggested that Ssb's function may be limited to the protection of nascent polypeptides from aggregation until downstream chaperones take over and actively fold their substrates. There is also evidence that Ssb, in parallel to a classical chaperone function, is involved in the regulation of cellular signaling processes. Here we aim to summarize what is currently known about Ssb's multiple functions and what remains to be ascertained by future research.
|
|
