Sperm-egg fusion proteins have same structure as those used by … – Phys.Org

February 14, 2017 by Kevin Hattori Transmission electron micrograph (TEM) of Zika virus. Credit: Cynthia Goldsmith/Centers for Disease Control and Prevention

The protein that helps the sperm and egg fuse together in sexual reproduction can also fuse regular cells together. Recent findings by a team of biomedical researchers from the Technion-Israel Institute of Technology, Argentina, Uruguay and the U.S. show this protein is part of a larger family of proteins that helps other cells bind together to create larger organs, and which also allows viruses like Zika and Dengue to invade healthy cells.

For every sexually reproducing organism, sperm and egg fusion is the first step in the generation of a new individual. This process has been studied for more than 100 years in many organisms including humans, mice, insects, plants, sea urchins and even fungi. But the identity of the molecular machineries that mediate sperm and egg fusion remained unknown.

Now, the team led by Dr. Benjamin Podbilewicz, of the Technion Faculty of Biology, and Dr. Pablo S. Aguilar of Universidad Nacional de San Martin in Argentina, has demonstrated that the protein HAP2 a long known player in sperm-egg fusion is a protein that mediates a broad range of cell-cell fusion. Their findings were published recently in the Journal of Cell Biology.

HAP2 is found in plants, protists (e.g. algae, protozoa, and slime molds) and invertebrates, and is therefore considered an ancestral protein present at the origins of the first eukaryotic cells (cells with real nuclei). However, a closer look at HAP2 led the researchers to conclude that HAP2's roots are even older. Structural and phylogenetic analysis of HAP2 proteins revealed they are homologous to proteins used by viruses such as Zika and Dengue to fuse viral membrane to the membrane of the cell they invade.

According to the researchers, this means HAP2, FF and viral fusion proteins constitute a superfamily of membrane fusion proteins, which the authors named Fusexins (fusion proteins essential for sexual reproduction and exoplasmic merger of plasma membranes).

"Fusexins are fascinating machines that keep a structural core diversified to execute cell membrane fusion in very different contexts," says Prof. Podbilewicz. "Understanding the different structure-function relationships of fusexins will enable scientists to rationally manipulate cell-cell fusion in fertilization and tissue development. The added and very timely benefit is that it provides us greater understanding of how Zika and other viruses cause diseases in their target hosts."

The striking similarities between proteins that promote membrane fusion under very different contexts led the authors to dig into mechanistic details. Performing cell-cell fusion experiments, the researchers demonstrated that, like FF fusexins, HAP2 is needed in both fusing cells to promote membrane cell fusion. This bilateral requirement of HAP2 and FF fusexins differs from the viral mechanism of action, where fusexin is only present in the viral membrane (see figure).

The combined conservation of structure, sequence, and function imply that these proteins diverged from a common ancestor. Fusexins might have emerged 2-3 billion years ago to promote a primordial form of genetic material exchange between cells. Later, enveloped viruses took these fusion proteins to infect cells more efficiently. Finally, multicellular organisms adapted fusexins to sculpt organs like muscle and bone-repairing osteoclasts in vertebrates and skin and the vagina in worms through cell-cell fusion.

Explore further: Researchers Uncover Cell Fusion Mechanism

More information: Clari Valansi et al. HAP2/GCS1 is a gamete fusion protein homologous to somatic and viral fusogens, The Journal of Cell Biology (2017). DOI: 10.1083/jcb.201610093

Journal reference: Journal of Cell Biology

Provided by: Technion-Israel Institute of Technology

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Mutant Maize Offers Key to Understanding Plant Growth – UCR Today (press release)

Live cell time-lapse imaging of maize mutant provides crucial details for UC Riverside researchers

By Sean Nealon on February 13, 2017

From left, normal and mutant maize plants.

RIVERSIDE, Calif. (www.ucr.edu) How plant cells divide and how that contributes to plant growth has been one of the longstanding unsolved mysteries of cell biology. Two conflicting ideas have fueled the mystery.

The first idea is that cells divide merely to fill space in plant tissue, and therefore the orientation of the division is unimportant to growth. In other words, the contribution of individual cell behavior to overall growth isnt very important.

The second idea is that individual cells are the basic unit of life and their individual programs eventually build an organism. In other words, each new cell created contributes to proper patterning of the tissue. In this case, the orientation of each cells division is critical for how the plant tissue is patterned and also impacts growth.

New findings by a University of California, Riverside-led team of researchers, lend support to the second idea, that the orientation of cell division is critical for overall plant growth. The work was just published in the journal Proceedings of the National Academy of Sciences.

The researchers, led by Carolyn Rasmussen, an assistant professor of plant cell biology at UC Riverside and Pablo Martinez, a graduate student working in Rasmussens lab, together with Anding Luo and Anne Sylvester at University of Wyoming, were working with a maize mutant, called tangled1, with known defects in growth and division plane orientation of cells. Division plane orientation refers to the positioning of new cell walls during division.

Scanning electron micrographs of maize epidermal cells. Left is the mutant variety. Right is the wild variety.

They used time-lapse live cell imaging that represented hundreds of hours of maize, (commonly called corn in the United States), cells dividing. The time-lapse of imaging allowed them to characterize a previously unknown delay during cell division stages in the maize mutant. This study clarified the relationship between growth, timely division progression and proper division plane orientation.

This study suggests that delays during division do not necessarily cause growth defects, but that improper placement of new cell walls together with delays during division causes growth defects. Therefore, division plane orientation is a critical but potentially indirect factor for growth.

The findings might have long-term implications for increasing agricultural production. For example, during the Green Revolution of the mid-20th century, researchers developed short-stature, or dwarf, wheat and rice varieties that led to higher yields and are credited with saving over a billion people from starvation. Understanding the molecular mechanisms of plant growth might contribute in the long-term to developing more suitable short-stature maize varieties.

The paper is called Proper division plane orientation and mitotic progression together allow normal growth of maize.

Archived under: Science/Technology, Carolyn Rasmussen, College of Natural and Agricultural Sciences, Department of Botany and Plant Sciences, Pablo Martinez, press release

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Anatomy of a heart attack – goskagit.com

HEART ATTACKS HAPPEN to both women and menbut they dont always look the same. Theyre not as obvious as youd see on TV, and thats true for more women than men.

Heres a look at what makes recognizing a heart attack so importantand why noticing more subtle signs is especially important for women.

What to look for

What does a heart attack feel like? Chest pain or discomfort is the most common symptom for both women and men. The pain may last a few minutes or come and go. Some people say it feels like pressure, squeezing, or fullness. Or it may feel like an upset stomach or heartburn.

But women are more likely than men to have other heart attack signs, says Paul Connor, MD, PeaceHealth Medical Group Cardiology, in Bellingham.

Those may include:

Shortness of breath with or without chest pain

Nausea, lightheadedness, or vomiting

Unexplained fatigue that may last for days

Back, shoulder, arm or jaw pain

Women are also at higher risk for silent heart attacks, according to some studies. This is when symptoms of a heart attack are so mild that they go unnoticedor are dismissed as anxiety.

Silent heart attacks are just as dangerous as more obvious heart attacks, though, says Dr. Connor. Left untreated, they can cause scarring and permanent damage, raising the risk of other heart problems.

So dont be too quick to dismiss shortness of breath or lightheadedness as just anxiety. And make sure you tell medical professionals that you think youre having a heart attack, not an anxiety attack.

A supply problem at the pump

Despite womens more subtle symptoms, the mechanics of a heart attack are fundamentally the same for both sexes. It happens when the hearts blood supply is reduced or cut off, most often when an artery becomes blocked.

What usually sets the stage? Doctors call it atherosclerosis. It happens when arteries that bring blood to the heart slowly become clogged with plaque. A blood clot can form around these plaques, causing complete obstruction of the blood flow to the heart muscle.

Without prompt treatment, areas of heart muscle may die and eventually be replaced by scars. This damage could leave a heart attack survivor with a weakened heart.

And a weak heart may not be able to pump blood to the bodys organs like it should, which could result in other quality-of-life issues, Dr. Connor says.

Quick treatment can restore blood flow to the heart and help prevent damage. So be aware of these warning signs for both yourself and others. If theres even a slight chance you could be having a heart attack, dont wait. Call 911 and get to a hospital to give your heart the best chance.

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Anatomy class teaches several lessons – Seguin Gazette: Editorials – Seguin Gazette-Enterprise

Recently, a group of high school students, under the direction of anatomy teacher Daniel Sanchez visited Vogel Elementary and taught all of the second grade students a little lesson.

The subject a human cell.

While this may seem a little outside the younger students realm of understanding, the teens delivered the lesson in a way the youngsters could understand.

Prior to the visit, Sanchez, wanted to make sure his students understood the lesson and tasked them with writing a childrens story.

By using the terminology and definitions, his students received an easier way to remember what they have learned.

What he didnt expect to happen was to see that lesson evolve beyond his classroom, and spill over into the elementary classroom.

As Sanchez students read their stories to the second graders, the children eagerly listened and then asked questions.

They also got to see what a human cell looks like thanks to the models the teens also created for their class, unknowing that it would become a prop for this special session.

Not only did the high school students learn, but they taught their younger counterparts, solidifying what they learned.

They became role models for the younger students, and helped them engage in conversations.

They created a new curiosity for science, and quite possibly an interest that can lead to things beyond what they imagined.

Our Voice is the opinion of the Seguin Gazette editorial board.

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Anatomy class teaches several lessons - Seguin Gazette: Editorials - Seguin Gazette-Enterprise

Seattle Genetics Earnings: Waiting on ECHELON – Motley Fool

2017 is looking like a transition year for the biotech.

Seattle Genetics (NASDAQ:SGEN) released fourth-quarter earnings on Thursday and gave investors a taste of what's to come later this year. With modest growth for Adcetris, its only drug on the market, investors should be focused on Seattle Genetics' pipeline and clinical trials that could further expand sales of Adcetris.

Metric

Q4 2016

Q4 2015

Year-Over-Year Change

Revenue

$105 million

$93 million

12.6%

Income from operations

($55.8 million)

($25.1 million)

N/A

Earnings per share

($0.39)

($0.18)

N/A

Data source: Seattle Genetics.

Image source: Getty Images.

Clay Siegall, Seattle Genetics' president and CEO, asked investors to look past 2017 guidance and see the bigger picture: "What is really important with Adcetris is not the sales we have now. What's really important is going toward the big items of [ECHELON-1] and [ECHELON-2], and you can even include ALCANZA in there."

On the delay of submitting the application for CTCL patients, Siegall didn't even want to call it that. "To me it's not a delay. To me it's taking advantage of an opportunity," he said. "I think we have a really good opportunity to end up with a bigger market if we can get a bigger label."

Management guided for Adcetris sales of $280 million to $300 million this year, which is 5.3% to 12.9% higher than last year's sales. Royalty revenue is expected to be in the $50 million to $55 million range, down from the $67.5 million in 2016, but last year included a $20 million milestone payment.

The difference between the bottom and top of guidance likely has to do with how many doctors prescribe Adcetris for CTCL off-label ahead of the FDA approval. But capturing those patients now versus next year isn't particularly important for Seattle Genetics' long-term value.

Brian Orelli has no position in any stocks mentioned. The Motley Fool recommends Seattle Genetics. The Motley Fool has a disclosure policy.

Dr. Orelli is a Senior Biotech Specialist. He has written about biotech, pharmaceutical, and medical device companies for The Motley Fool since 2007.

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Biotech Premarket Movers: Sage Therapeutics, Immunomedics, Myriad Genetics – TheStreet.com

Shares of Sage Therapeutics ( SAGE) were up 8.6% ahead of the opening bell on Monday, trading at $51.50. The Cambridge, Mass. company unveiled encouraging top-line results from part A of its phase 2 study of SAGE-217 for the treatment of major depressive disorder. "Understanding the caveats associated with open-label data, we are highly encouraged by the strong signal we achieved in this study, which met our internal criteria for achieving a positive signal and thus supported our plan to proceed to the double-blind, placebo-controlled part of the Phase 2 trial," said Sage CEO Jeff Jonas in a statement.

Meanwhile, Immunomedics ( IMMU) shares rose 8% to $5.65 after finishing Friday's trading session at $5.23, up 21.6%. The Morris Plains, N.J. company on Friday announced a global licensing agreement with Seattle Genetics ( SGEN) for sacituzumab govitecan, Immunomedics' solid tumor therapy candidate.

Other biotech stock movers on Monday morning include molecular diagnostic company Myriad Genetics ( MYGN) , whose shares were up 6.2%, to $16.98.

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Biotech Premarket Movers: Sage Therapeutics, Immunomedics, Myriad Genetics - TheStreet.com

Cocaine addiction a matter of genetics, UBC researchers say – Calgary Herald

Scientists at the University of B.C.have built a better mouse one that is indifferent to cocaine.

Unlike normal mice, the genetically engineered rodents did not show addictive behaviour even after repeated injections of the narcotic over days, suggesting that habitual drug use in humans may be a matter of genetics.

While the finding is unlikely to yield a pill that cures addiction anytime soon, it could lead to a test that identifies who is at greatest risk of addiction and enable people to act on that knowledge, saidShernaz Bamji, the lead author of a study published today by the journal Nature Neuroscience.

The finding provides a biochemical model for addiction based onprevious work at Johns Hopkins University in Baltimore, Md., that found people with genetic mutations associated with a class of proteins in the brain called cadherins are more prone to substance abuse.

Cadherin helps bind cells together and play a role inwhich brain circuits are strengthened during learning even learning that certain drugs deliver pleasure.

Although Bamji had theorized that higher levels of cadherin would lead to more addictive behaviour, the opposite turned out to be true.

To better understand its role, the researchers engineered mice to produce excessive cadherin proteins in their brains.

Bamji and her collaboratorsinjected normal and genetically engineered mice with cocaine and placed them in a distinctly decorated room within a multi-room cage. On alternating days the mice were placed in the other room and injected with saline, said co-author Andrea Globa.

After six days of alternating treatments, the mice wereallowed to move freely to any of the rooms in the cage.

The normal mice greatly preferred the cocaine-associated room, but the high-cadherin mice didnt much care for it, suggesting that the presence of extra cadherin had somehow interfered with the learned response to cocaine.

Normal mice always gravitate to the chamber where they received the drug, looking for that high, but the mutant mice didnt, said Bamji.

The answer to the mysterious result was found inside the membrane of brain cellsthemselves, where cadherin interfered with the ability of a specialized proteinreceptor to functionat the synapse, the point at which neurons communicatewith each other chemically toform memories.

Unable to strengthen the connection between synapses, the brains learning circuitry couldntretaincocaines pleasurable memory.

Addiction is a form of learning in the reward circuits of the brain, she said. Where you dont get synapse strengthening, you arent getting learning and you arent getting addiction.

However, because many synapsesin the brain use the same strategy to learn, a magic bullet or pill for addiction is a long way off.

Simply increasing cadherin would likely prevent (addicts)from learning anything new, she said. Thats not a very good trade-off.

Future research might uncover a protein or enzyme in the brainmore specific to addiction that functions only in the reward circuitry of the brain, which could be a target for medication.

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College of Medicine graduate student launches genetics research start-up – Penn State News

HERSHEY, Pa. Olivier Noel is only 28 years old, but hes already changing the face of genetics research.

The Haitian native is in his sixth year of Penn State College of MedicinesMD/PhD Medical Scientist Training Programand was recently recognized by Forbes as one of the countrys brightest young entrepreneurs on its30 Under 30 list in the science industry. Hes the founder of DNAsimple, a startup aimed at accelerating genetics research by connecting DNA donors with research scientists. The company provides scientists with access to critically important samples, significantly speeding up the pace for genetics research.

People dont realize it can take years to get samples, but really only a month to get an assignment done which is a little bit ridiculous, Noel said. Its a problem for geneticists across the board. You can have a million dollars to do a study, but waste three years trying to get samples.

Noel explained a light bulb went off when he attended a genetics conference at the recommendation of Dr. Roger L. Ladda, whom he had been shadowing with the intent of focusing his residency on genetics.

The keynote speaker at the conference was talking about how he was studying a disease not really prevalent in the Western world, and the way they were able to get a DNA sample to validate was through Facebook. The joke at the time was that Facebook is the new way of doing genetics. I realized, wow, that worked well for one case but thats not the way science should get done, Noel said.

Noels big break was when the company was accepted into the Y Combinator program, which includes such notable alumni as Dropbox, Airbnb and Reddit. DNAsimple was one of 32 companies accepted from more than 6,500 applicants worldwide, he said. But he credits his doctoral advisors former Penn State faculty member Dr. Glenn S. Gerhard and Penn State College of Medicine Chair of Biochemistry and Molecular BiologyJames Broach for teaching him about genetics and exposing him to the Penn State Institute for Personalized Medicine.

Learn more about Noel and his work in this Penn State Medicine article.

Last Updated February 13, 2017

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Genetics of height: It may be too complex for scientists to crack the code – Genetic Literacy Project

[W]hen the human genome was sequenced, scientists like [Joel Hirschhorn, a geneticist at Boston Childrens Hospital and the Broad Institute] thought they could plumb that data to track all the height genes.

That effort started slowly. But now, Hirschhorn says, For height there are about 700 variants known to affect height, each of them usually with a pretty small effect on height, usually like a millimeter or less.

Even so, the traits [Hirschhorn] found only explain about a quarter of the inherited height factors. And, frustratingly, for most of those variants scientists have no idea what they actually do.

Hirschhorn and his colleagues are expanding their already massive study of 700,000 subjects. That approach has drawn skepticism from some scientists, who think its a waste of effort.

David Goldstein, a professor of genetics at Columbia University, says an expanded effort could ultimately implicate every gene in existence, and that hardly helps scientists narrow down the biological factors that contribute to height.

Its likely scientists will never be able to figure out what these hundreds of common variants do to influence height, Goldstein says. Instead, a much better strategy is [to look] for rare variants that pack a big punch.

[The study can be found here.]

The GLP aggregated and excerpted this blog/article to reflect the diversity of news, opinion, and analysis. Read full, original post:Genetics of Height is Way Complex, It Turns Out

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miRagen Therapeutics (MGEN) Completes Merger with Signal Genetics (SGNL) – StreetInsider.com

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Miragen Therapeutics, Inc. (Nasdaq: MGEN), a clinical-stage biopharmaceutical company focused on the discovery and development of microRNA-targeted therapies, today announced the completion of its merger with Signal Genetics, Inc. (Nasdaq: SGNL) , effective February 13, 2017. Concurrent with the closing of the merger, miRagen received gross proceeds of $40.7 million in new equity investment from a combination of current and new miRagen investors, including Fidelity Management and Research Company, Brace Pharma Capital, Atlas Venture, Boulder Ventures, JAFCO Co., Ltd., MP Healthcare Venture Management, MRL Ventures (a venture fund of Merck, known as MSD outside the United States and Canada), Remeditex Ventures, and others. Together with pre-merger cash on miRagens balance sheet, the combined company has approximately $60 million in cash and short-term investments.

Upon completion of the merger today, Signal was renamed Miragen Therapeutics, Inc. The combined company will commence trading on The NASDAQ Capital Market under the symbol MGEN on February 14, 2017.

The completion of this merger marks a significant step forward for miRagen, our investors and potentially thousands of patients awaiting a therapeutic option for their conditions, said miRagen President and CEO William S. Marshall, Ph.D. The equity investment aligns the companys cash resources with our plan to advance the first two clinical programs into additional trials and to develop a compelling pipeline of targeted product candidates, each focused on patient populations with few clinical options. We believe these transactions will help us create a more focused and well financed organization as we build an exciting enterprise, an innovative culture and value for current and future stockholders.

Following the completion of the financing and merger, the combined company has approximately 21.3 million shares of common stock outstanding.

miRagens stockholders, including those who invested in the concurrent financing, received common stock, representing approximately 95.2% of the outstanding shares. Signals stockholders retained approximately 4.8% of the combined company.

The combined company will operate under the leadership of Dr. Marshall, and the board of directors of the combined company is comprised of seven members: Bruce Booth, John Creecy, Thomas Hughes, Kevin Koch, Kyle Lefkoff, Joseph Turner and Dr. Marshall.

Wedbush PacGrow acted as placement agent for miRagen in the financing.

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