Termite sensitivity to temperature affects global wood decay rates.

Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing >6.8 times per 10°C increase in temperature)-even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth's surface

Dynein and Dynactin Leverage Their Bivalent Character to Form a High-Affinity Interaction

Amanda E. Siglin is with Thomas Jefferson University, Shangjin Sun is with University of Delaware, Jeffrey K. Moore is with Washington University in Saint Louis, Sarah Tan is with UT Austin, Martin Poenie is with UT Austin, James D. Lear is with University of Pennsylvania, Tatyana Polenova is with University of Delaware, John A. Cooper is with Washington University in Saint Louis, and John C. Williams is with Thomas Jefferson University and Beckman Research Institute at City of Hope.Cytoplasmic dynein and dynactin participate in retrograde transport of organelles, checkpoint signaling and cell division. The principal subunits that mediate this interaction are the dynein intermediate chain (IC) and the dynactin p150Glued; however, the interface and mechanism that regulates this interaction remains poorly defined. Herein, we use multiple methods to show the N-terminus of mammalian dynein IC, residues 10–44, is sufficient for binding p150Glued. Consistent with this mapping, monoclonal antibodies that antagonize the dynein-dynactin interaction also bind to this region of the IC. Furthermore, double and triple alanine point mutations spanning residues 6 to 19 in the yeast IC homolog, Pac11, produce significant defects in spindle positioning. Using the same methods we show residues 381 to 530 of p150Glued form a minimal fragment that binds to the dynein IC. Sedimentation equilibrium experiments indicate that these individual fragments are predominantly monomeric, but admixtures of the IC and p150Glued fragments produce a 2:2 complex. This tetrameric complex is sensitive to salt, temperature and pH, suggesting that the binding is dominated by electrostatic interactions. Finally, circular dichroism (CD) experiments indicate that the N-terminus of the IC is disordered and becomes ordered upon binding p150Glued. Taken together, the data indicate that the dynein-dynactin interaction proceeds through a disorder-to-order transition, leveraging its bivalent-bivalent character to form a high affinity, but readily reversible interaction.This work was supported in part by National Institutes of Health R21NS071166 (J.C.W.), R01GM085306 (J.C.W. & T.P.), NCRR SRR022316A (J.C.W.), GM 47337 (J.A.C.), NCRR 5P20RR017716-07 (T.P.), 5-T32-DK07705 (A.E.S) and The American Heart Association 0715196U (A.E.S). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Cellular and Molecular Biolog

Recruitment of dynein to late endosomes and lysosomes through light intermediate chains

How cytoplasmic dynein is recruited to diverse organelles remains incompletely understood. Using the first subcellular localization of LIC isoforms, along with RNAi, RILP, and dynactin dominant negatives, the LIC subunits are found to recruit dynein specifically to components of the late endocytic pathway through a dynactin-independent mechanism

The role of motor proteins in endosomal sorting

Abstract Microtubule motor proteins play key roles in the spatial organization of intracellular organelles as well as the transfer of material between them. This is well illustrated both by the vectorial transfer of biosynthetic cargo from the endoplasmic reticulum to the Golgi apparatus as well as the sorting of secretory and endocytic cargo in the endosomal system. Roles have been described for dynein and kinesin motors in each of these steps. Cytoplasmic dynein is a highly complex motor comprising multiple subunits that provide functional specialization. The family of human kinesins includes over 40 members. This complexity provides immense functional diversity, yet little is known of the specific requirements and functions of individual motors during discrete membrane trafficking steps. In the present paper, we describe some of the latest findings in this area that seek to define the mechanisms of recruitment and control of activity of microtubule motors in spatial organization and cargo trafficking through the endosomal network

Termite sensitivity to temperature affects global wood decay rates

Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing &gt;6.8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface.</p

Termite Sensitivity to Temperature Affects Global Wood Decay Rates

Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing \u3e6.8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface

Termite sensitivity to temperature affects global wood decay rates

Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing >6.8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface.Fil: Zanne, Amy E.. The George Washington University; Estados Unidos. University of Miami; Estados UnidosFil: Flores Moreno, Habacuc. University of Queensland; AustraliaFil: Powell, Jeff R.. University of Western Sydney; AustraliaFil: Cornwell, William K.. University of New South Wales; AustraliaFil: Dalling, James W.. University of Illinois. Urbana - Champaign; Estados Unidos. Smithsonian Tropical Research Institute; PanamáFil: Austin, Amy Theresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Classen, Aimée T.. University of Michigan; Estados UnidosFil: Eggleton, Paul. Natural History Museum; Reino UnidoFil: Okada, Kei Ichi. Tokyo University of Agriculture; JapónFil: Parr, Catherine. University of Liverpool; Reino Unido. University Of Pretoria; Sudáfrica. University of the Witwatersrand; SudáfricaFil: Carol Adair, E.. University of Vermont; Estados UnidosFil: Adu Bredu, Stephen. Council For Scientific And Industrial Research Ghana; Ghana. Csir - Forestry Research Institute Of Ghana; GhanaFil: Alam, Md Azharul. Lincoln University.; Nueva ZelandaFil: Alvarez Garzón, Carolina. Universidad Colegio Mayor de Nuestra Señora del Rosario; ColombiaFil: Apgaua, Deborah. The School For Field Studies; AustraliaFil: Aragón, Myriam Roxana. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Ardon, Marcelo. North Carolina State University; Estados UnidosFil: Arndt, Stefan K.. School Of Ecosystem And Forest Science; AustraliaFil: Ashton, Louise A.. The University Of Hong Kong; Hong KongFil: Barber, Nicholas A.. Northern Illinois University; Estados UnidosFil: Beauchêne, Jacques. Université Des Antilles; FranciaFil: Berg, Matty P.. University of Groningen; Países Bajos. Vrije Universiteit Amsterdam; Países BajosFil: Beringer, Jason. University of Western Australia; AustraliaFil: Boer, Matthias M.. Hawkesbury Institute For The Environment; AustraliaFil: Bonet, José Antonio. AGROTECNIO; EspañaFil: Bunney, Katherine. University Of Pretoria; SudáfricaFil: Burkhardt, Tynan J.. University of Auckland; Nueva ZelandaFil: Carvalho, Dulcinéia. Universidad Federal de Lavras; BrasilFil: Castillo Figueroa, Dennis. Universidad Colegio Mayor de Nuestra Señora del Rosario; ColombiaFil: Cernusak, Lucas A.. James Cook University; Australi

Specificity of Cytoplasmic Dynein Subunits in Discrete Membrane-trafficking Steps

The cytoplasmic dynein motor complex is known to exist in multiple forms, but few specific functions have been assigned to individual subunits. A key limitation in the analysis of dynein in intact mammalian cells has been the reliance on gross perturbation of dynein function, e.g., inhibitory antibodies, depolymerization of the entire microtubule network, or the use of expression of dominant negative proteins that inhibit dynein indirectly. Here, we have used RNAi and automated image analysis to define roles for dynein subunits in distinct membrane-trafficking processes. Depletion of a specific subset of dynein subunits, notably LIC1 (DYNC1LI1) but not LIC2 (DYNC1LI2), recapitulates a direct block of ER export, revealing that dynein is required to maintain the steady-state composition of the Golgi, through ongoing ER-to-Golgi transport. Suppression of LIC2 but not of LIC1 results in a defect in recycling endosome distribution and cytokinesis. Biochemical analyses also define the role of each subunit in stabilization of the dynein complex; notably, suppression of DHC1 or IC2 results in concomitant loss of Tctex1. Our data demonstrate that LIC1 and LIC2 define distinct dynein complexes that function at the Golgi versus recycling endosomes, respectively, suggesting that functional populations of dynein mediate discrete intracellular trafficking pathways

Termite sensitivity to temperature affects global wood decay rates

Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing >6.8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface

Termite sensitivity to temperature affects global wood decay rates

Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing >6.8 times per 10°C increase in temperature)—even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth’s surface