TY  - JOUR
A1  - Sanges, C.
A1  - Scheuermann, C.
A1  - Zahedi, R. P.
A1  - Sickmann, A.
A1  - Lamberti, A.
A1  - Migliaccio, N.
A1  - Baljuls, A.
A1  - Marra, M.
A1  - Zappavigna, S.
A1  - Reinders, J.
A1  - Rapp, U.
A1  - Abbruzzese, A.
A1  - Caraglia, M.
A1  - Arcari, P.
T1  - Raf kinases mediate the phosphorylation of eukaryotic translation elongation factor 1A and regulate its stability in eukaryotic cells
JF  - Cell Death and Disease
N2  - We identified eukaryotic translation elongation factor 1A (eEF1A) Raf-mediated phosphorylation sites and defined their role in the regulation of eEF1A half-life and of apoptosis of human cancer cells. Mass spectrometry identified in vitro S21 and T88 as phosphorylation sites mediated by B-Raf but not C-Raf on eEF1A1 whereas S21 was phosphorylated on eEF1A2 by both B- and C-Raf. Interestingly, S21 belongs to the first eEF1A GTP/GDP-binding consensus sequence. Phosphorylation of S21 was strongly enhanced when both eEF1A isoforms were preincubated prior the assay with C-Raf, suggesting that the eEF1A isoforms can heterodimerize thus increasing the accessibility of S21 to the phosphate. Overexpression of eEF1A1 in COS 7 cells confirmed the phosphorylation of T88 also in vivo. Compared with wt, in COS 7 cells overexpressed phosphodeficient (A) and phospho-mimicking (D) mutants of eEF1A1 (S21A/D and T88A/D) and of eEF1A2 (S21A/D), resulted less stable and more rapidly proteasome degraded. Transfection of S21 A/D eEF1A mutants in H1355 cells increased apoptosis in comparison with the wt isoforms. It indicates that the blockage of S21 interferes with or even supports C-Raf induced apoptosis rather than cell survival. Raf-mediated regulation of this site could be a crucial mechanism involved in the functional switching of eEF1A between its role in protein biosynthesis and its participation in other cellular processes.
KW  - EF-1A
KW  - Raf kinases
KW  - signal transduction
KW  - apoptosis
KW  - ubiquitin
KW  - mass spectrometry
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124149
VL  - 3
IS  - e276
ER  - 
TY  - JOUR
A1  - Sanges, C.
A1  - Scheuermann, C.
A1  - Zahedi, R. P.
A1  - Sickmann, A.
A1  - Lamberti, A.
A1  - Migliaccio, N.
A1  - Baljuls, A.
A1  - Marra, M.
A1  - Zappavigna, S.
A1  - Rapp, U.
A1  - Abbruzzese, A.
A1  - Caraglia, M.
A1  - Arcari, P.
T1  - Raf kinases mediate the phosphorylation of eukaryotic translation elongation factor 1A and regulate its stability in eukaryotic cells
JF  - Cell Death & Disease
N2  - We identified eukaryotic translation elongation factor 1A (eEF1A) Raf-mediated phosphorylation sites and defined their role in the regulation of eEF1A half-life and of apoptosis of human cancer cells. Mass spectrometry identified in vitro S21 and T88 as phosphorylation sites mediated by B-Raf but not C-Raf on eEF1A1 whereas S21 was phosphorylated on eEF1A2 by both B-and C-Raf. Interestingly, S21 belongs to the first eEF1A GTP/GDP-binding consensus sequence. Phosphorylation of S21 was strongly enhanced when both eEF1A isoforms were preincubated prior the assay with C-Raf, suggesting that the eEF1A isoforms can heterodimerize thus increasing the accessibility of S21 to the phosphate. Overexpression of eEF1A1 in COS 7 cells confirmed the phosphorylation of T88 also in vivo. Compared with wt, in COS 7 cells overexpressed phosphodeficient (A) and phospho-mimicking (D) mutants of eEF1A1 (S21A/D and T88A/D) and of eEF1A2 (S21A/D), resulted less stable and more rapidly proteasome degraded. Transfection of S21 A/D eEF1A mutants in H1355 cells increased apoptosis in comparison with the wt isoforms. It indicates that the blockage of S21 interferes with or even supports C-Raf induced apoptosis rather than cell survival. Raf-mediated regulation of this site could be a crucial mechanism involved in the functional switching of eEF1A between its role in protein biosynthesis and its participation in other cellular processes.
KW  - signal transduction
KW  - mass spectrometry
KW  - elongation
KW  - protein docking
KW  - factor EEF1A2
KW  - cancer-cells
KW  - lung cancer
KW  - EF-1A
KW  - Raf kinases
KW  - aminoacyl-transfer-RNA
KW  - tyrosine phosphorylation
KW  - factor 1-alpha
KW  - nucleotide exchange
KW  - polyarcylamide gels
KW  - chain
KW  - apoptosis
KW  - ubiquitin
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134673
VL  - 3
IS  - e276
ER  - 
TY  - JOUR
A1  - Viljur, Mari‐Liis
A1  - Abella, Scott R.
A1  - Adámek, Martin
A1  - Alencar, Janderson Batista Rodrigues
A1  - Barber, Nicholas A.
A1  - Beudert, Burkhard
A1  - Burkle, Laura A.
A1  - Cagnolo, Luciano
A1  - Campos, Brent R.
A1  - Chao, Anne
A1  - Chergui, Brahim
A1  - Choi, Chang‐Yong
A1  - Cleary, Daniel F. R.
A1  - Davis, Thomas Seth
A1  - Dechnik‐Vázquez, Yanus A.
A1  - Downing, William M.
A1  - Fuentes‐Ramirez, Andrés
A1  - Gandhi, Kamal J. K.
A1  - Gehring, Catherine
A1  - Georgiev, Kostadin B.
A1  - Gimbutas, Mark
A1  - Gongalsky, Konstantin B.
A1  - Gorbunova, Anastasiya Y.
A1  - Greenberg, Cathryn H.
A1  - Hylander, Kristoffer
A1  - Jules, Erik S.
A1  - Korobushkin, Daniil I.
A1  - Köster, Kajar
A1  - Kurth, Valerie
A1  - Lanham, Joseph Drew
A1  - Lazarina, Maria
A1  - Leverkus, Alexandro B.
A1  - Lindenmayer, David
A1  - Marra, Daniel Magnabosco
A1  - Martín‐Pinto, Pablo
A1  - Meave, Jorge A.
A1  - Moretti, Marco
A1  - Nam, Hyun‐Young
A1  - Obrist, Martin K.
A1  - Petanidou, Theodora
A1  - Pons, Pere
A1  - Potts, Simon G.
A1  - Rapoport, Irina B.
A1  - Rhoades, Paul R.
A1  - Richter, Clark
A1  - Saifutdinov, Ruslan A.
A1  - Sanders, Nathan J.
A1  - Santos, Xavier
A1  - Steel, Zachary
A1  - Tavella, Julia
A1  - Wendenburg, Clara
A1  - Wermelinger, Beat
A1  - Zaitsev, Andrey S.
A1  - Thorn, Simon
T1  - The effect of natural disturbances on forest biodiversity: an ecological synthesis
JF  - Biological Reviews
N2  - Disturbances alter biodiversity via their specific characteristics, including severity and extent in the landscape, which act at different temporal and spatial scales. Biodiversity response to disturbance also depends on the community characteristics and habitat requirements of species. Untangling the mechanistic interplay of these factors has guided disturbance ecology for decades, generating mixed scientific evidence of biodiversity responses to disturbance. Understanding the impact of natural disturbances on biodiversity is increasingly important due to human‐induced changes in natural disturbance regimes. In many areas, major natural forest disturbances, such as wildfires, windstorms, and insect outbreaks, are becoming more frequent, intense, severe, and widespread due to climate change and land‐use change. Conversely, the suppression of natural disturbances threatens disturbance‐dependent biota. Using a meta‐analytic approach, we analysed a global data set (with most sampling concentrated in temperate and boreal secondary forests) of species assemblages of 26 taxonomic groups, including plants, animals, and fungi collected from forests affected by wildfires, windstorms, and insect outbreaks. The overall effect of natural disturbances on α‐diversity did not differ significantly from zero, but some taxonomic groups responded positively to disturbance, while others tended to respond negatively. Disturbance was beneficial for taxonomic groups preferring conditions associated with open canopies (e.g. hymenopterans and hoverflies), whereas ground‐dwelling groups and/or groups typically associated with shady conditions (e.g. epigeic lichens and mycorrhizal fungi) were more likely to be negatively impacted by disturbance. Across all taxonomic groups, the highest α‐diversity in disturbed forest patches occurred under moderate disturbance severity, i.e. with approximately 55% of trees killed by disturbance. We further extended our meta‐analysis by applying a unified diversity concept based on Hill numbers to estimate α‐diversity changes in different taxonomic groups across a gradient of disturbance severity measured at the stand scale and incorporating other disturbance features. We found that disturbance severity negatively affected diversity for Hill number q = 0 but not for q = 1 and q = 2, indicating that diversity–disturbance relationships are shaped by species relative abundances. Our synthesis of α‐diversity was extended by a synthesis of disturbance‐induced change in species assemblages, and revealed that disturbance changes the β‐diversity of multiple taxonomic groups, including some groups that were not affected at the α‐diversity level (birds and woody plants). Finally, we used mixed rarefaction/extrapolation to estimate biodiversity change as a function of the proportion of forests that were disturbed, i.e. the disturbance extent measured at the landscape scale. The comparison of intact and naturally disturbed forests revealed that both types of forests provide habitat for unique species assemblages, whereas species diversity in the mixture of disturbed and undisturbed forests peaked at intermediate values of disturbance extent in the simulated landscape. Hence, the relationship between α‐diversity and disturbance severity in disturbed forest stands was strikingly similar to the relationship between species richness and disturbance extent in a landscape consisting of both disturbed and undisturbed forest habitats. This result suggests that both moderate disturbance severity and moderate disturbance extent support the highest levels of biodiversity in contemporary forest landscapes.
KW  - natural disturbance
KW  - diversity–disturbance relationship
KW  - disturbance severity
KW  - disturbance extent
KW  - intermediate disturbance hypothesis
KW  - forest communities
KW  - α‐diversity
KW  - β‐diversity
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-287168
VL  - 97
IS  - 5
SP  - 1930
EP  - 1947
ER  -