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Mechanotransduction in talin through the interaction of the R8 domain with DLC1

PLOS Biology (new articles) - Fri, 2018-07-20 23:00

by Alexander William M. Haining, Rolle Rahikainen, Ernesto Cortes, Dariusz Lachowski, Alistair Rice, Magdalena von Essen, Vesa P. Hytönen, Armando del Río Hernández

The mechanical unfolding of proteins is a cellular mechanism for force transduction with potentially broad implications in cell fate. Despite this, the mechanism by which protein unfolding elicits differential downstream signalling pathways remains poorly understood. Here, we used protein engineering, atomic force microscopy, and biophysical tools to delineate how protein unfolding controls cell mechanics. Deleted in liver cancer 1 (DLC1) is a negative regulator of Ras homolog family member A (RhoA) and cell contractility that regulates cell behaviour when localised to focal adhesions bound to folded talin. Using a talin mutant resistant to force-induced unfolding of R8 domain, we show that talin unfolding determines DLC1 downstream signalling and, consequently, cell mechanics. We propose that this new mechanism of mechanotransduction may have implications for a wide variety of associated cellular processes.
Categories: Biology, Journals

Genome-wide maps of ribosomal occupancy provide insights into adaptive evolution and regulatory roles of uORFs during <i>Drosophila</i> development

PLOS Biology (new articles) - Fri, 2018-07-20 23:00

by Hong Zhang, Shengqian Dou, Feng He, Junjie Luo, Liping Wei, Jian Lu

Upstream open reading frames (uORFs) play important roles in regulating the main coding DNA sequences (CDSs) via translational repression. Despite their prevalence in the genomes, uORFs are overall discriminated against by natural selection. However, it remains unclear why in the genomes there are so many uORFs more conserved than expected under the assumption of neutral evolution. Here, we generated genome-wide maps of translational efficiency (TE) at the codon level throughout the life cycle of Drosophila melanogaster. We identified 35,735 uORFs that were expressed, and 32,224 (90.2%) of them showed evidence of ribosome occupancy during Drosophila development. The ribosome occupancy of uORFs is determined by genomic features, such as optimized sequence contexts around their start codons, a shorter distance to CDSs, and higher coding potentials. Our population genomic analysis suggests the segregating mutations that create or disrupt uORFs are overall deleterious in D. melanogaster. However, we found for the first time that many (68.3% of) newly fixed uORFs that are associated with ribosomes in D. melanogaster are driven by positive Darwinian selection. Our findings also suggest that uORFs play a vital role in controlling the translational program in Drosophila. Moreover, we found that many uORFs are transcribed or translated in a developmental stage-, sex-, or tissue-specific manner, suggesting that selective transcription or translation of uORFs could potentially modulate the TE of the downstream CDSs during Drosophila development.
Categories: Biology, Journals

The sun shrinks and grows again by 2 kilometres every 11 years

Genetics - Fri, 2018-07-20 18:29
The sun’s size changes throughout its 11-year cycle of magnetic activity, and measuring that growth may help us figure out what’s going on inside
Categories: Biology

Why weird star systems are where we’ll find alien life

Genetics - Fri, 2018-07-20 17:00
In the hunt for life beyond Earth, we've been looking for planets and stars like our own. But that is flawed – and a new plan promises answers in our lifetimes
Categories: Biology

Movie studio AI predicts who will like a film based on its trailer

Genetics - Fri, 2018-07-20 16:10
It’s difficult to know who will like a film, so 20th Century Fox have built an AI that watches movie trailers and predicts who’s most likely to go see it
Categories: Biology

Movie studio AI predicts who will like a film based on its trailer

HIV and AIDS - Fri, 2018-07-20 16:10
It’s difficult to know who will like a film, so 20th Century Fox have built an AI that watches movie trailers and predicts who’s most likely to go see it

How dodgy sausages are saving a cute marsupial from toxic toads

Genetics - Fri, 2018-07-20 16:00
In a true-life alien versus predator story, a touch of food poisoning could save an endangered Australian species from a relentless toxic tide
Categories: Biology

We’ve started to uncover the true purpose of dreams

Genetics - Fri, 2018-07-20 16:00
For the first time, researchers have got evidence that dreams help soothe the impact of emotional events in our lives, acting like overnight therapy
Categories: Biology

We’ve started to uncover the true purpose of dreams

HIV and AIDS - Fri, 2018-07-20 16:00
For the first time, researchers have got evidence that dreams help soothe the impact of emotional events in our lives, acting like overnight therapy

Baby poo reveals that even light drinking during pregnancy affects IQ

Genetics - Fri, 2018-07-20 15:51
Occasional drinking during pregnancy may affect IQ, according to a study that tested newborn babies’ faeces to see if their mothers had consumed alcohol
Categories: Biology

Baby poo reveals that even light drinking during pregnancy affects IQ

HIV and AIDS - Fri, 2018-07-20 15:51
Occasional drinking during pregnancy may affect IQ, according to a study that tested newborn babies’ faeces to see if their mothers had consumed alcohol

The truth about intelligence: How useful is a high IQ?

Genetics - Fri, 2018-07-20 14:00
A smart brain might help you do well in tests, but there are many other ways it can affect your life, both positively and negatively
Categories: Biology

Fewer baby boys were born after three major earthquakes in Japan

Genetics - Fri, 2018-07-20 13:21
A lower proportion of boys were born nine months after Japan’s three worst earthquakes in recent history, suggesting stress makes it harder to conceive males
Categories: Biology

Fewer baby boys were born after three major earthquakes in Japan

HIV and AIDS - Fri, 2018-07-20 13:21
A lower proportion of boys were born nine months after Japan’s three worst earthquakes in recent history, suggesting stress makes it harder to conceive males

Feedback: Gulls just wanna have fun

Genetics - Fri, 2018-07-20 12:00
Boozy birds crash land in the UK. Plus: ominous sarcophagus, bullet train gets a boost, authorities lose the scent of mystery pooper, and more
Categories: Biology

Hair cell identity establishes labeled lines of directional mechanosensation

PLOS Biology (new articles) - Thu, 2018-07-19 23:00

by Marta Lozano-Ortega, Gema Valera, Yan Xiao, Adèle Faucherre, Hernán López-Schier

Directional mechanoreception by hair cells is transmitted to the brain via afferent neurons to enable postural control and rheotaxis. Neuronal tuning to individual directions of mechanical flow occurs when each peripheral axon selectively synapses with multiple hair cells of identical planar polarization. How such mechanosensory labeled lines are established and maintained remains unsolved. Here, we use the zebrafish lateral line to reveal that asymmetric activity of the transcription factor Emx2 diversifies hair cell identity to instruct polarity-selective synaptogenesis. Unexpectedly, presynaptic scaffolds and coherent hair cell orientation are dispensable for synaptic selectivity, indicating that epithelial planar polarity and synaptic partner matching are separable. Moreover, regenerating axons recapitulate synapses with hair cells according to Emx2 expression but not global orientation. Our results identify a simple cellular algorithm that solves the selectivity task even in the presence of noise generated by the frequent receptor cell turnover. They also suggest that coupling connectivity patterns to cellular identity rather than polarity relaxes developmental and evolutionary constraints to innervation of organs with differing orientation.
Categories: Biology, Journals

If we’re in the Meghalayan, whatever happened to the Anthropocene?

Genetics - Thu, 2018-07-19 19:00
The decision to label our current geological phase the Meghalayan rather than the Anthropocene is misguided, say Mark Maslin and Simon Lewis
Categories: Biology

If we’re in the Meghalayan, whatever happened to the Anthropocene?

Genetically modified organisms (GMO) - Thu, 2018-07-19 19:00
The decision to label our current geological phase the Meghalayan rather than the Anthropocene is misguided, say Mark Maslin and Simon Lewis
Categories: Science and society

If we’re in the Meghalayan, whatever happened to the Anthropocene?

HIV and AIDS - Thu, 2018-07-19 19:00
The decision to label our current geological phase the Meghalayan rather than the Anthropocene is misguided, say Mark Maslin and Simon Lewis

Spectacular new photos of Titan show Saturn’s moon like never before

Genetics - Thu, 2018-07-19 18:35
Saturn’s moon Titan is shrouded in a thick orange haze, but 13 years of data from the Cassini spacecraft have allowed us to peer through to the frozen surface
Categories: Biology