| 1. |
- Eriksson, Emma, 1980, et al.
(författare)
-
A microfluidic system in combination with optical tweezers for analyzing rapid and reversible cytological alterations in single cells upon environmental changes
- 2007
-
Ingår i: Lab on a chip. - : Royal Society of Chemistry (RSC). - 1473-0197 .- 1473-0189. ; 7:1, s. 71-76
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the development of an experimental platform where epi-fluorescence microscopy and optical tweezers are combined with a microfluidic system to enable the analysis of rapid cytological responses in single cells. The microfluidic system allows two different media to be merged in a Y-shaped channel. Microscale channel dimensions ensure purely laminar flow and, as a result, an environmental gradient can be created between the two media. Optical tweezers are used to move a single trapped cell repeatedly between the different environments. The cell is monitored continuously by fluorescence microscopy during the experiment. In a first experiment on yeast (Saccharomyces cerevisiae) we observed changes in cell volume as the cell was moved between environments with different osmolarity. This demonstrated that the platform allowed analysis of cytological alterations on a time scale shorter than 0.2 s. In a second experiment we observed the spatial migration of the Yap1p transcription factor fused to GFP as a cell was moved from an environment of low to high oxidative capacity. The system is universal allowing the response to numerous environmental changes to be studied on the sub second time scale in a variety of model cells. We intend to use the platform to study how the age of cells, their progression through the cell cycle, or their genetic landscape, alter their capacity (kinetics and amplitude) to respond to environmental changes.
|
|
| 2. |
- Erjavec, Nika, 1977, et al.
(författare)
-
Accelerated aging and failure to segregate damaged proteins in Sir2 mutants can be suppressed by overproducing the protein aggregation-remodeling factor Hsp104p
- 2007
-
Ingår i: GENES & DEVELOPMENT. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 21:19, s. 2410-2421
-
Tidskriftsartikel (refereegranskat)abstract
- The levels of oxidatively damaged, carbonylated, proteins increase with the replicative age of yeast mother cells. We show here that such carbonylated proteins are associated with Hsp104p-containing protein aggregates and that these aggregates, like oxidized proteins, are retained in the progenitor cell during cytokinesis by a Sir2p-dependent process. Deletion of HSP104 resulted in a breakdown of damage asymmetry, and overproduction of Hsp104p partially restored damage retention in sir2Δ cells, suggesting that functional chaperones associated with protein aggregates are required for the establishment of damage asymmetry and that these functions are limited in sir2Δ cells. In line with this, Hsp104p and several Hsp70s displayed elevated damaged in sir2Δ cells, and protein aggregates were rescued at a slower rate in this mutant. Moreover, overproduction of Hsp104p suppressed the accelerated aging of cells lacking Sir2p, and drugs inhibiting damage segregation further demonstrated that spatial quality control is required to rejuvenate the progeny.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Schekhuber, C. Q., et al.
(författare)
-
Reducing mitochondrial fission results in increased life span and fitness of two fungal ageing models
- 2007
-
Ingår i: Nature Cell Biology. - : Springer Science and Business Media LLC. - 1465-7392 .- 1476-4679. ; 9:1
-
Tidskriftsartikel (refereegranskat)abstract
- Ageing of biological systems is accompanied by alterations in mitochondrial morphology, including a transformation from networks and filaments to punctuate units1. The significance of these alterations with regard to ageing is not known. Here, we demonstrate that the dynamin-related protein 1 (Dnm1p), a mitochondrial fission protein conserved from yeast to humans2, affects ageing in the two model systems we studied, Podospora anserina and Saccharomyces cerevisiae. Deletion of the Dnm1 gene delays the transformation of filamentous to punctuate mitochondria and retards ageing without impairing fitness and fertility typically observed in long-lived mutants. Our data further suggest that reduced mitochondrial fission extends life span by increasing cellular resistance to the induction of apoptosis and links mitochondrial dynamics, apoptosis and life-span control
|
|
