EvoLiteracy News 04 14 2015

Today’s EvoLiteracy News are sushi-, ultra-small nano-lanterns-, and bird-malaria related. The “Wasabi Receptor” protein has been 3D-characterized (watch video); the technology offers insights for possible drug-design to manage pain. “Nano-lanterns” genetically engineered to illuminate inside cells. Plus, recent studies of bird blood parasites, including avian malaria, suggest a likely center of speciation (high diversity) and endemism in Malawi. And a treat: watch a cool animation by TED Ed about ‘How we think complex cells evolved’ via endosymbiosis — GPC. 

“Wasabi Receptor” research featured in journal Nature. Yes, it is about the inseparable and irritant sushi companion!

Wasabi Receptor Images

Wasabi and ‘wasabi receptor’ 3D images. Click on image for links to UCSF press release.

The article, authored by Paulsen and four other collaborators, most currently affiliated with the University of California San Francisco, is titled Structure of the TRPA1 Ion Channel Suggests Regulatory Mechanisms. The UCSF press release highlights the research as a “First Look at ‘Wasabi Receptor’ Brings Insights for Pain Drug Development… Protein’s Structure Will Guide Hunt for New Treatments of Inflammation-Induced Pain…”

“TRPA1, the newly visualized protein resides in the cellular membrane of sensory nerve cells. It detects chemical agents originating outside our bodies —pungent irritants found in substances ranging from wasabi to tear gas— but is also triggered by pain-inducing signals originating within, especially those that arise in response to tissue damage and inflammation.”

The authors formally summarize the science as follows: “The TRPA1 ion channel (also known as the wasabi receptor) is a detector of noxious chemical agents encountered in our environment or produced endogenously during tissue injury or drug metabolism. These include a broad class of electrophiles that activate the channel through covalent protein modification. TRPA1 antagonists hold potential for treating neurogenic inflammatory conditions provoked or exacerbated by irritant exposure. Despite compelling reasons to understand TRPA1 function, structural mechanisms underlying channel regulation remain obscure. Here we [Paulsen et al.] use single-particle electron cryo-microscopy to determine the structure of full-length human TRPA1 to 4A resolution in the presence of pharmacophores, including a potent antagonist. Several unexpected features are revealed, including an extensive coiled-coil assembly domain stabilized by polyphosphate co-factors and a highly integrated nexus that converges on an unpredicted transient receptor potential ( TRP)-like allosteric domain. These findings provide new insights into the mechanisms of TRPA1 regulation, and establish a blueprint for structure-based design of analgesic and anti-inflammatory agents.” For original scientific paper go to Nature.

Below, watch 1:10-min ‘Wasabi Receptor’ video released by UCSF:


Ultra small “nano-lanterns” genetically engineered to illuminate cell structures and study them from the inside out. Work published in the Proceedings of the National Academy of Sciences.

Nano-Lantern PNAS 04 07 2015

Time-lapse dual-color luminescent imaging of cyan and orange colored cells. Click on image to watch video.

Takai et al. (total nine coauthors) titled their article Expanded Palette of Nano-lanterns for Real-time Multicolor Luminescence Imaging. The authors highlight the significance of their findings as follows: “The application of luminescence imaging has been limited mainly by the two drawbacks of luciferases: low brightness and poor color variants. [Takai et al.] report the development of cyan and orange luminescent proteins approximately 20 times brighter than the wild-type Renilla luciferase. The color change and enhancement of brightness were both achieved by exploring bioluminescence resonance energy transfer (BRET) from enhanced Renilla luciferase to a fluorescent protein, a technology that [the researchers] previously reported for the development of the bright yellowish-green luminescent protein Nano-lantern. These cyan and orange Nano-lanterns along with the original yellow Nano-lantern enable monitoring of multiple cellular events, including dynamics of subcellular structures, gene expressions, and functional status, such as intracellular Ca2+ change.” For complete study and video images go to PNAS.

The summarized article’s abstract reads: “…The brightness of these cyan and orange Nano-lanterns… allowed [Takai et al.] to perform multicolor live imaging of intracellular submicron structures. The rapid dynamics of endosomes and peroxisomes were visualized at around 1-s temporal resolution, and the slow dynamics of focal adhesions were continuously imaged for longer than a few hours without photobleaching or photodamage. In addition, [the researchers] extended the application of these multicolor Nano-lanterns to simultaneous monitoring of multiple gene expression or Ca2+ dynamics in different cellular compartments in a single cell.” Read more in PNAS.

79% of Malawi’s birds infected with blood parasites. High parasite diversity and endemism suggest Malawi’s ecosystems might have been the center of avian malaria origins; PLoS ONE.

Lutz et al. (total eight coauthors) titled their article Parasite Prevalence Corresponds to Host Life History in a Diverse Assemblage of Afrotropical Birds and Haemosporidian Parasites. The authors tested the hypothesis that life history traits of Afrotropical birds predict rates of parasitism by haemosporidian parasites (including Plasmodium, Haemoproteus and Leucocytozoon). Lutz et al. included in their analyses “traits known to be associated with host-vector encounter rates (for example, nest type, nest placement and flocking behavior).” They “combined taxonomic sampling of host species from a wide variety of habitats and life histories in Northern Malawi with the application of PCR-based methods to detect rates of parasitism.” In addition, Lutz et al. documented an “unprecedented prevalence of Plasmodium, Haemoproteus and Leucocytozoon infections across a broad range of birds belonging to 16 orders, 50 families, 100 genera, and 152 species.”

Avian Malaria

Mosquito biting a bird’s eye, where skin is exposed. Avian blood cell infested with Haemoproteus (center of image).

“Birds with closed cup nests experienced increased rates of Plasmodium infection and decreased rates of Haemoproteus infection, whereas cavity-nesting birds experienced increased rates of Leucocytozoon infection” But, perhaps most significantly, the authors found that “Haemosporidian prevalence in birds from… Malawi [was] higher than… other tropical regions… The results suggest that the Afrotropics is an area of high… endemicity and diversity… Southeastern Africa is… an important region in which to investigate… host-parasite associations, speciation, and the evolution of malaria parasites and other closely related haemosporidians.”

Lutz et al. formally summarize the research as follows: “Avian host life history traits have been hypothesized to predict rates of infection by haemosporidian parasites. Using molecular techniques, we tested this hypothesis for parasites from three haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon) collected from a diverse sampling of birds in northern Malawi. We found that host life history traits were significantly associated with parasitism rates by all three parasite genera. Nest type and nest location predicted infection probability for all three parasite genera, whereas flocking behavior is an important predictor of Plasmodium and Haemoproteus infection and habitat is an important predictor of Leucocytozoon infection. Parasite prevalence was 79.1% across all individuals sampled, higher than that reported for comparable studies from any other region of the world. Parasite diversity was also exceptionally high, with 248 parasite cytochrome b lineages identified from 152 host species. A large proportion of Plasmodium, Haemoproteus, and Leucocytozoon parasite DNA sequences identified in this study represent new, previously undocumented lineages (n = 201; 81% of total identified) based on BLAST queries against the avian malaria database, MalAvi.” Read complete open access study in PLoS ONE.

Video: How we think complex cells evolved – Adam Jacobson TED Ed Lessons – Imagine you swallowed a small bird and suddenly gained the ability to fly … or you ate a cobra and were able to spit poisonous venom! Well, throughout the history of life (and specifically during the evolution of complex eukaryotic cells) things like this happened all the time. Adam Jacobson explains endosymbiosis, a type of symbiosis in which one symbiotic organism lives inside another.