Nestin, an intermediate filament protein widely used as a marker of neural progenitors, was recently found to be expressed transiently in developing cortical neurons in culture and in developing mouse cortex. In young cortical cultures, nestin regulates axonal growth cone morphology. In addition, nestin, which is known to bind the neuronal cdk5/p35 kinase, affects responses to axon guidance cues upstream of cdk5, specifically, to Sema3a. Changes in growth cone morphology require rearrangements of cytoskeletal networks, and changes in microtubules and actin filaments are well studied. In contrast, the roles of intermediate filament proteins in this process are poorly understood, even in cultured neurons. Here, we investigate the molecular mechanism by which nestin affects growth cone morphology and Sema3a sensitivity. We find that nestin selectively facilitates the phosphorylation of the lissencephaly-linked protein doublecortin (DCX) by cdk5/p35, but the phosphorylation of other cdk5 substrates is not affected by nestin. We uncover that this substrate selectivity is based on the ability of nestin to interact with DCX, but not with other cdk5 substrates. Nestin thus creates a selective scaffold for DCX with activated cdk5/p35. Last, we use cortical cultures derived from Dcx KO mice to show that the effects of nestin on growth cone morphology and on Sema3a sensitivity are DCX-dependent, thus suggesting a functional role for the DCX-nestin complex in neurons. We propose that nestin changes growth cone behavior by regulating the intracellular kinase signaling environment in developing neurons. The sex of animal subjects is unknown.

SIGNIFICANCE STATEMENT Nestin, an intermediate filament protein highly expressed in neural progenitors, was recently identified in developing neurons where it regulates growth cone morphology and responsiveness to the guidance cue Sema3a. Changes in growth cone morphology require rearrangements of cytoskeletal networks, but the roles of intermediate filaments in this process are poorly understood. We now report that nestin selectively facilitates phosphorylation of the lissencephaly-linked doublecortin (DCX) by cdk5/p35, but the phosphorylation of other cdk5 substrates is not affected. This substrate selectivity is based on preferential scaffolding of DCX, cdk5, and p35 by nestin. Additionally, we demonstrate a functional role for the DCX-nestin complex in neurons. We propose that nestin changes growth cone behavior by regulating intracellular kinase signaling in developing neurons.

Eradicating hunger must be accompanied by strenuous efforts to end malnutrition and its devastating effects. That was a pivotal message at the launch of FAO’s key publication The State of Food and Agriculture, which this year focuses on Food systems for better nutrition. “FAO’s message is that we must strive for nothing less than the eradication of hunger and malnutrition,” said Director-General [...]

Help raise the profile of the IYFF 2014 and its role in eradicating hunger Family farming is the predominant form of agriculture in the world with more than 500 million family farmers playing a key role in securing a future where more quality food is produced in a sustainable way.  For this reason, the 2014 International Year of Family Farming plays a [...]

Today leading international experts on climate change, the IPCC, presented their latest report on the impacts of climate change on humanity, and what we can do about it. It’s a lengthy report, so we’ve shrunk it down to Oxfam's five key takeaways on climate change and hunger. 1. Climate change: the impacts on crops are worse than we thought Climate change has [...]

Malnutrition isn’t just a problem of hunger in developing countries—it exists in all regions and across socio-economic classes. The effects on human health Besides undernutrition, malnutrition also includes micronutrient-deficient diets and overweight and obesity. Chronic malnutrition can have serious, often life-threatening, health consequences, especially for children. Undernutrition can lead to physical and cognitive stunting, and makes children more susceptible to infectious diseases. Micronutrient deficiencies [...]

As part of a balanced diet, milk and dairy products can be an important source of dietary energy, protein and fat. But, the scientific evidence is massing up that regular consumption of large quantities of milk can be bad for your health, and campaigners are making noise about the environmental and international costs of large-scale intensive dairy farming. We put together [...]

E-learning was quite the buzzword a couple of decades ago – then when the internet started in earnest it became even more so. Today e-learning is mainstreamed in many organization, including FAO with more than 400 000 learners taking advantage of FAO’s offerings. FAO’s e-learning center offers free interactive courses – in English, French and Spanish - on topics ranging [...]

On the frontline of climate change, effects are real and measurable. As climate change evolves, food and agriculture need to follow suit. Rising temperatures, changes in rainfall, erratic weather patterns and the prevalence of pests and diseases resulting from climate change threaten agricultural productivity and therefore undermine global food security. Simultaneously, the world’s population is growing steadily and expected to reach [...]

Climate change is what most of us perceive as the top global threat, and the dangers it poses affect present and future generations alike.  How global warming is threatening the planet has been a theme in children’s books for all ages for some time.   How everyone, especially today’s youth, can make a difference to the future of the world [...]

Over the past years, we have often been reminded that we must leave no one behind as we strive to cement our plans for a sustainable future. Most recent data indicate that many of the Small Island Developing States (SIDS) have achieved undernourishment levels of less than 5 percent. Good governance is perhaps the most essential factor in increasing food [...]

Forests are one of nature’s great providers. A source of water and food security, they also give us everything from paper and medicine to renewable energy, low-tech air conditioning and air cleansers. They also protect and enrich biodiversity and are a major tool in the fight against climate change. Ask several people what a forest is and their answers will probably [...]

It is well known that forests, especially rainforests, are key allies in our fight against climate change as they absorb greenhouse gas emissions. But did you know that oceans are the earth’s main buffer against climate change? In fact, about 25 percent of the greenhouse gases that we emit actually gets absorbed by the oceans, as does over 90 percent [...]

Perhaps from outer space, it is easy to get the perspective that we only have one earth and that it is succumbing to climate change. Seeing the earth from space though is a feat that, unfortunately, most of us will never accomplish. We have to rely on Astronaut Thomas Pesquet and the other brave women and men astronauts to provide [...]

Laxmi Sunar wants to provide her daughter with the best possible education so that she can have a bright future. This is Laxmi’s dream; it is the dream that all mothers have for their children. Today though, Laxmi’s main concern is that her family has enough food to eat.

In some countries, mountains are considered deities. In others, mountains are peaks to climb. In others still, mountains, like volcanoes, are spirits that can be angered. In countries around the world though, mountains provide life-sustaining water, energy and food for over half the world’s population.

The terraced hills of the Andes, the rice paddies of southern China, the oasis systems of the Maghreb: agriculture molds landscapes and places. Agriculture also shapes livelihoods, lifestyles, food traditions and cultures. What kind of plants grow or can’t grow, how they are harvested and what people eat define people’s lives.  Because our natural resources are under great strain, we need [...]

Last year, Ashmita Thapa’s husband left their hometown in southern Nepal to find work in Saudi Arabia. He had been working as a farmer and used to be able to grow enough food for the family. But now, Ashmita explains, the yields are poorer and poorer. “This is a part of climate change,” she adds. “There isn’t as much rain as [...]

Schools are an ideal setting for teaching basic skills in food, nutrition and health. In many communities, they may be the only place where children acquire these important life skills. Primary schools, in particular, are suitable vehicles for nutrition education. They not only influence children but also target girls, who tend to leave schools earlier. Nutrition lessons can be simple, [...]

All over the world, holidays mean the return of certain specialties: Olivier salad for New Year’s in Russia, Red bean porridge for solstice in Korea, Haleem for Ramadan in India and the Middle East, Mince pies for Christmas in England, Pogača bread for Orthodox Easter, Banana cakes for Lunar New Year in Vietnam. Whatever the holiday is and wherever in [...]

Growing crops, fishing, harvesting fruits and nuts from the forests are just some examples of the activities that millions of people do daily to get food to eat or to earn a living. But when their rights to that land or those natural resources aren’t recognized, livelihoods and food sources can disappear from one day to the next.    

Imagine living in one of the driest areas on the planet. What little rain there is falls over the space of a few months, yielding around 700 mm in total each year. A population of 1.2 million has to survive on 65 percent less water than the rest of their compatriots, on a traditional staple diet of corn and beans. [...]

A review of FAO’s fight against hunger and malnutrition and challenges ahead with the participation of José Graziano da Silva, Director-General of FAO. 

Where: Sheikh Zayed Centre at FAO headquarters 

When: Friday, 26th [...]

The Board of the Full Article