Global assessment of marine and freshwater recreational fish reveals mismatch in climate change vulnerability and conservation effort.

Recreational fisheries contribute substantially to the sociocultural and economic well-being of coastal and riparian regions worldwide, but climate change threatens their sustainability. Fishery managers require information on how climate change will impact key recreational species; however, the absence of a global assessment hinders both directed and widespread conservation efforts. In this study, we present the first global climate change vulnerability assessment of recreationally targeted fish species from marine and freshwater environments (including diadromous fishes).

Molecular underpinnings of cytoskeletal cross-talk.

Cross-talk between the microtubule and actin networks has come under intense scrutiny following the realization that it is crucial for numerous essential processes, ranging from cytokinesis to cell migration. It is becoming increasingly clear that proteins long-considered highly specific for one or the other cytoskeletal system do, in fact, make use of both filament types. How this functional duality of "shared proteins" has evolved and how their coadaptation enables cross-talk at the molecular level remain largely unknown.

Feeling the force: formin's role in mechanotransduction.

Fundamental cellular processes such as division, polarization, and motility require the tightly regulated spatial and temporal assembly and disassembly of the underlying actin cytoskeleton. The actin cytoskeleton has been long viewed as a central player facilitating diverse mechanotransduction pathways due to the notion that it is capable of receiving, processing, transmitting, and generating mechanical stresses. Recent work has begun to uncover the roles of mechanical stresses in modulating the activity of key regulatory actin-binding proteins and their interactions with actin filaments, thereby controlling the assembly (formin and Arp2/3 complex) and disassembly (ADF/Cofilin) of actin filament networks.

Mechanoregulated inhibition of formin facilitates contractile actomyosin ring assembly.

Cytokinesis physically separates dividing cells by forming a contractile actomyosin ring. The fission yeast contractile ring has been proposed to assemble by Search-Capture-Pull-Release from cytokinesis precursor nodes that include the molecular motor type-II myosin Myo2 and the actin assembly factor formin Cdc12. By successfully reconstituting Search-Capture-Pull in vitro, we discovered that formin Cdc12 is a mechanosensor, whereby myosin pulling on formin-bound actin filaments inhibits Cdc12-mediated actin assembly.

In Vitro Biochemical Characterization of Cytokinesis Actin-Binding Proteins.

Characterizing the biochemical and biophysical properties of purified proteins is critical to understand the underlying molecular mechanisms that facilitate complicated cellular processes such as cytokinesis. Here we outline in vitro assays to investigate the effects of cytokinesis actin-binding proteins on actin filament dynamics and organization. We describe (1) multicolor single-molecule TIRF microscopy actin assembly assays, (2) "bulk" pyrene actin assembly/disassembly assays, and (3) "bulk" sedimentation actin filament binding and bundling assays.

Actin age orchestrates myosin-5 and myosin-6 run lengths.

Unlike a static and immobile skeleton, the actin cytoskeleton is a highly dynamic network of filamentous actin (F-actin) polymers that continuously turn over. In addition to generating mechanical forces and sensing mechanical deformation, dynamic F-actin networks serve as cellular tracks for myosin motor traffic. However, much of our mechanistic understanding of processive myosins comes from in vitro studies in which motility was studied on pre-assembled and artificially stabilized, static F-actin tracks.

Disassembly activity of actin-depolymerizing factor (ADF) is associated with distinct cellular processes in apicomplexan parasites.

Proteins of the actin-depolymerizing factor (ADF)/cofilin family have been shown to be crucial for the motility and survival of apicomplexan parasites. However, the mechanisms by which ADF proteins fulfill their function remain poorly understood. In this study, we investigate the comparative activities of ADF proteins from Toxoplasma gondii and Plasmodium falciparum, the human malaria parasite, using a conditional T.

In vitro reconstitution of an mRNA-transport complex reveals mechanisms of assembly and motor activation.

The assembly and composition of ribonucleic acid (RNA)-transporting particles for asymmetric messenger RNA (mRNA) localization is not well understood. During mitosis of budding yeast, the Swi5p-dependent HO expression (SHE) complex transports a set of mRNAs into the daughter cell. We recombinantly reconstituted the core SHE complex and assessed its properties.

Diffusion of myosin V on microtubules: a fine-tuned interaction for which E-hooks are dispensable.

Organelle transport in eukaryotes employs both microtubule and actin tracks to deliver cargo effectively to their destinations, but the question of how the two systems cooperate is still largely unanswered. Recently, in vitro studies revealed that the actin-based processive motor myosin V also binds to, and diffuses along microtubules. This biophysical trick enables cells to exploit both tracks for the same transport process without switching motors.