ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Unknown

Migrate or stay: Terrestrial primary productivity and climate drive anadromy in Arctic char (2012)

Anders G. Finstad, Catherine L. Hein

Wiley

In: Global Change Biology

add to mindlist on the mindlist

Details

Publication Date: 2012-04-17

Description: A shift in the magnitude and timing of animal migrations is one of the most documented ecological effects of climate change. Although migrations are largely driven by spatial variation in resource gradients, few studies connect expected changes in primary production with geographical patterns in migratory behavior. Here, we link lake primary production to the occurrence of sea migrations in the partially anadromous salmonid Arctic char ( Salvelinus alpinus L.). We compiled presence/absence records of anadromous char populations spanning productivity and temperature gradients along the Norwegian coast. The probability of anadromy decreased with increasing migration distance, maximum slope of the migration route and lake productivity. There was a significant interaction between lake productivity and migration distance. The negative effect of longer migration distances was more severe in lakes with higher productivity, indicating reduced relative profitability of migration with increased feeding opportunities in freshwater. Lake productivity was mainly driven by terrestrial primary production in the catchment. We predicted future distributions of anadromous char given downscaled temperature and precipitation changes projected by two different emission scenarios and global climate models (GCMs). Projected increases in temperature and precipitation in 2071-2100 increased terrestrial primary production and, compared to the control scenario (1961-1990), decreased the range of anadromous populations. The prevalence of anadromy decreased by 53% in the HadAm3H GCM with the A2 emission scenario, 61% in HadAm3H with the B2 scenario and 22% in ECHAM4 with the B2 scenario. Cross-ecosystem studies (e.g., terrestrial to freshwater) are critical for understanding ecological impacts of climate change. In this case, climate-driven increases in terrestrial primary production are expected to increase primary production in lakes and ultimately reduce the prevalence of anadromy in Arctic char populations.

Print ISSN: 1354-1013

Electronic ISSN: 1365-2486

Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography

Published by Wiley

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

PAPER CURRENT

S·F·X

Fulltext

Unknown

A bimodular mechanism of calcium control in eukaryotes (2012)

H. Tidow ; L. R. Poulsen ; A. Andreeva ; [et al.]

Nature Publishing Group (NPG)

In: Nature. 491(7424): 468-72. doi: 10.1038/nature11539.

add to mindlist on the mindlist

Details

Publication Date: 2012-10-23

Description: Calcium ions (Ca(2+)) have an important role as secondary messengers in numerous signal transduction processes, and cells invest much energy in controlling and maintaining a steep gradient between intracellular ( approximately 0.1-micromolar) and extracellular ( approximately 2-millimolar) Ca(2+) concentrations. Calmodulin-stimulated calcium pumps, which include the plasma-membrane Ca(2+)-ATPases (PMCAs), are key regulators of intracellular Ca(2+) in eukaryotes. They contain a unique amino- or carboxy-terminal regulatory domain responsible for autoinhibition, and binding of calcium-loaded calmodulin to this domain releases autoinhibition and activates the pump. However, the structural basis for the activation mechanism is unknown and a key remaining question is how calmodulin-mediated PMCA regulation can cover both basal Ca(2+) levels in the nanomolar range as well as micromolar-range Ca(2+) transients generated by cell stimulation. Here we present an integrated study combining the determination of the high-resolution crystal structure of a PMCA regulatory-domain/calmodulin complex with in vivo characterization and biochemical, biophysical and bioinformatics data that provide mechanistic insights into a two-step PMCA activation mechanism mediated by calcium-loaded calmodulin. The structure shows the entire PMCA regulatory domain and reveals an unexpected 2:1 stoichiometry with two calcium-loaded calmodulin molecules binding to different sites on a long helix. A multifaceted characterization of the role of both sites leads to a general structural model for calmodulin-mediated regulation of PMCAs that allows stringent, highly responsive control of intracellular calcium in eukaryotes, making it possible to maintain a stable, basal level at a threshold Ca(2+) concentration, where steep activation occurs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tidow, Henning -- Poulsen, Lisbeth R -- Andreeva, Antonina -- Knudsen, Michael -- Hein, Kim L -- Wiuf, Carsten -- Palmgren, Michael G -- Nissen, Poul -- MC_U105192716/Medical Research Council/United Kingdom -- England -- Nature. 2012 Nov 15;491(7424):468-72. doi: 10.1038/nature11539. Epub 2012 Oct 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Centre for Membrane Pumps in Cells and Disease - PUMPKIN, Aarhus University, Gustav Wieds Vej 10c, DK-8000 Aarhus C, Denmark.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23086147" target="_blank"〉PubMed〈/a〉

Keywords: Amino Acid Sequence ; Arabidopsis/chemistry/enzymology/*metabolism ; Arabidopsis Proteins/*chemistry/genetics/*metabolism ; Binding Sites ; Calcium/*metabolism ; Calcium-Transporting ATPases/*chemistry/genetics/*metabolism ; Calmodulin/*chemistry/metabolism ; Enzyme Activation ; Eukaryota/*metabolism ; Intracellular Space/chemistry/metabolism ; Models, Molecular ; Molecular Sequence Data ; Protein Binding ; Protein Structure, Tertiary ; Sequence Alignment

Print ISSN: 0028-0836

Electronic ISSN: 1476-4687

Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics