Molecular motion in detail

first_imgIn a critical breakthrough in unraveling how molecular “motors” ferry proteins and nutrients through cells, Harvard scientists have produced high-resolution images that show how the “foot” of dynein — one of the most complex, but least understood such motors — binds to microtubules, the cellular tracks it travels on.As described in a Sept. 20 paper in Science, a team of researchers, led by Andres Leschziner, an associate professor of molecular and cellular biology in Harvard’s Department of Molecular and Cellular Biology, and Samara Reck-Peterson, an assistant professor of cell biology at Harvard Medical School, showed that dynein’s foot dramatically changes shape as it binds to the microtubule. Those chemical changes, Leschziner said, suggest that the foot acts as a sensor to aid coordinated movement.“In some ways, the idea that dynein is binding to the microtubule is not especially interesting,” Leschziner said. “What is truly exciting about this research is the finding that, because the foot changes shape as it binds, that somehow tells the ‘head’ what is happening. This finding completes the picture of how that communication works.”Understanding how that communication works, Leschziner said, is critical because, unless dynein’s walk is highly coordinated, the protein motor will simply fall off its microtubule track, and its cargo will be lost.That cargo, he explained, is critical to proper cell function.Though some cells can rely on diffusion to deliver proteins and nutrients throughout the cell, others — such as a neuron that ranges from your spine to the bottom of your foot — are simply too large for the process to work. They instead rely on molecular motors like dynein to deliver cargo to where it’s needed.“If you only relied on diffusion, it would take years for a molecule to diffuse to where it needed to be,” Leschziner said. “Microtubules act like freeways, allowing dynein and other molecular motors to quickly deliver proteins and nutrients where they’re needed.”To produce the first-ever high-resolution images of how dynein’s foot binds to microtubules, Leschziner and his team — including first authors Rogelio Antonio Hernandez-Lopez, a graduate student in Leschziner’s lab, and William Bret Redwine, a graduate student in both the Leschziner and Reck-Peterson labs — turned to a technique called cryo-electron microscopy.Researchers began by mixing two purified solutions — one made up of dynein “feet,” the other of microtubules — causing the feet to bind to the microtubules. A tiny amount of the resulting solution was then placed on a nanofabricated copper grid and embedded in a solution of vitreous ice.Using an electron microscope to capture images through the nanoscale holes in the copper grid, the researchers captured hundreds of images showing microtubules — and their attached dynein feet — in dozens of positions. Then they created a three-dimensional model showing how the foot binds to the microtubule.“The process is similar to the way a CT [computerized tomography] scan works — it takes images from different angles which can be projected into a 3-D image,” said Redwine. “In our case, we used computational tools to figure out how all those different views we had captured were related.”Armed with that new model and earlier models that showed the foot in its unbound state, researchers relied on molecular dynamics simulations — a process that calculates the interactions between atoms in molecules over time — to show how the unbound foot could transform into the bound configuration and back again as the motor moves.To confirm that their model was correct, Leschziner and his team took the research one step further, introducing mutations that computer simulations predicted would make dynein much more likely to bind to microtubules. The researchers predicted this would result in a dynein that walked farther along its track before dissociating.“What we found is that it walks slower, but it walks much further,” Hernandez-Lopez said. “In the paper, we suggest that may be a problem because dynein works together with other molecular motors that run on the same track but pull in the opposite direction, in a finely tuned tug of war. If you have a dynein that never lets go, that will cause a problem if the system needs to be dynamic.”Going forward, Leschziner said, he wants to understand the evolutionary issues that have impeded dynein.“We expected dynein to want to bind to the track all the time, but it seems to have evolved a system in which it isn’t bound as tightly,” he said. “What’s interesting is that dynein is optimal in terms of what it does in a cell, but that means being suboptimal in terms of its motor properties.”last_img read more

Bravo injury hands TKR captaincy to Pollard

first_imgTHE Trinbago Knight Riders (TKR) have appointed Kieron Pollard captain for the 2019 Hero CPL season. They came to the decision after Dwayne Bravo injured his finger during practice and could miss a significant part of the season.Pollard was picked in the 2019 Player Draft as TKR’s marquee player and the Trinidadian is set to represent his home franchise for the first time in the CPL.Venky Mysore, Director of TKR said,“It’s a very unfortunate injury and Dwayne Bravo will be greatly missed. However, we are fortunate to have someone of the calibre of Kieron Pollard to take over the reins from Bravo,” said Director of TKR Venky Mysore.“His leadership abilities are well proven and, like Bravo, will bring a very aggressive style as captain in TKR’s quest for a third championship in a row”.Pollard said he was happy to be able to stand in for the mercurial captain of the three-time champions.“I am standing in the shoes of the entertainer, Dwayne Bravo. I have been waiting for a long time to be made a part of this special team and I am happy to finally be here,” Pollard said.“This year, a couple of new guys like me have been given the opportunity to be a part of this great franchise. We are looking forward to putting in our best and lifting the title once again in 2019.”The Trinbago Knight Riders will start their campaign with a home game against St. Kitts & Nevis Patriots on Wednesday, September 4.(Sportsmax)last_img read more

Seniors defend Home Internationals title

first_img23 Sep 2015 Seniors defend Home Internationals title New British senior champion Julie Brown is in England’s seven-strong team to defend the Senior Women’s Home Internationals next week. The championship will be played at Elm Park Golf Club, Ireland, from Wednesday to Friday, September 30-October 2. The England team includes all six players (pictured top) who won the silver medal at the recent European senior ladies’ team championship, together with Cheshire’s Sue Dye (pictured below). The team is again captained by Huddersfield’s Pat Wrightson. The players: Caroline Berry (Bromborough) tied fifth in the British seniors and is a past winner of the English senior amateur and strokeplay titles. Julie Brown (Trentham) has just won the British senior championship at Prestatyn and is top of the England Golf senior women’s order of merit. Sue Dye (Delamere Forest) also tied 5th in the British seniors has won both the senior amateur and the senior stroke play titles on two occasions. Lulu Housman (Wyke Green) won the English senior stroke play and reached the quarter finals of the senior amateur. She made her debut for England seniors last year. Helen Lowe (Scraptoft) won the 2015 English senior women’s amateur, having made her debut in senior ranks last year. She tied eighth in the British senior championship. Cath Rawthore (Sale) won last year’s British senior championship, the English senior stroke play and finished top of the 2014 senior women’s order of merit. Lindsey Shaw (Chevin) was a semi-finalist at the English senior amateur and finished eighth at the stroke play. She was also runner-up in this season’s Spanish senior amateur.last_img read more

Red Bank Regional Proposing $22M Referendum

first_imgItems Include Classroom Expansion, Roof Replacement, New Turf Field |By Jay Cook |LITTLE SILVER – Residents of Little Silver, Red Bank and Shrewsbury Borough will be asked to vote on a two-part, $22-million referendum in December to fund a total roof replacement, classroom expansion and turf field installation at Red Bank Regional High School (RBR).An anticipated increase to student enrollment, the reduction of income from out-of-district students and a proactivity to expand programs for all students are driving the vote, said RBR Superintendent Louis Moore, Ph.D.“This is going to be the next crossroads” for RBR, Moore told The Two River Times Tuesday. “If this referendum goes forward, it’s going to put us in a place to continue to thrive. But if we lose, there are going to be some significant costs.”The referendum is set for Dec. 11 and will be split into two separate questions, with the second contingent upon approval of the first.The first is a projected $19.9 million bond to finance a total replacement of the high school’s roof which is “at the end of its life,” said Moore. It will also address an expansion to the school’s footprint creating 10 new classrooms along with transforming the media center into a “learning commons,” he said. This question qualifies for state debt service aid which the district projects would reduce the cost to $15.7 million.A second question, with a $2.2-million price tag, will fund replacing the existing grass stadium field with a new turf field, as well as upgrades to the concession stands and new bathroom facilities at the stadium. This question will only be approved if the first question passes, and it does not qualify for state debt service aid.With debt aid calculated in, the total project cost is roughly $18 million.Depending on average assessed home values in the three boroughs, homeowners would see a tax increase between $82 and $152 annually until 2023, when older debts are retired, according to a statement from the district. After 2023, the tax hit from this referendum would shrink to a range between $52 and $92.Here is a breakdown of the three towns with their average assessed home values and the tax levy based on those assessments using 2018-2019 budget information:Little Silver: Average Assessment = $633,785. Regional School Tax Levy = $2,728.67Red Bank: Average Assessment = $364,296. Regional School Tax Levy = $1,663.97Shrewsbury: Average Assessment = $496,184. Regional School Tax Levy = $2,508.13A combination of factors surrounding student enrollment is driving the referendum. Enrollment from in-district students is on the rise, said Moore. A demographic study commissioned last year shows an anticipated 5 to 10 percent increase in the student body. RBR has 1,217 students enrolled this year and its capacity is 1,200 students; that’s expected to jump to 1,350 in the coming years.The school is also seeing less money come in as increasing in-district enrollments have essentially barred out-of-district students. RBR drew 190 students from 15 different sending districts in the 2017-2018 school year at a tuition cost of $14,500 each. Tuition income to RBR has fallen from $4 million to $2.8 million over the past four years as the number of available spaces has declined.The district offers multiple unique Career Technical Educational academies drawing students from Belmar, Millstone and Union Beach, among others, Moore said. Those academies are for visual and performing arts, information technology, engineering and early childhood education.Moore added that the RBR Board of Education increases the out-of-district tuition roughly 2 percent annually, which is in line with the usual budget increases.Local taxpayers, however, will feel the brunt down the line if the referendum is denied, Moore cautioned.“I think this is a very responsible approach to these issues,” he said. “The truth is – and it’s a little counterintuitive – but if we don’t do this, the tax burden will actually increase.”The vote comes just before the tri-borough school district will celebrate its 50th anniversary in 2019. According to the school’s history, the original building was financed by voters in the three boroughs for a total cost of $9.4 million.“This is going to improve our facility and really let us take the next step in being able to offer remarkable programs to all of our students,” Moore said. “It’s also going to deal with these fiscal issues that we’re already seeing.”The Red Bank Regional High School District will be presenting referendum plans at borough meetings and for any groups that request it to inform the public. Questions about the vote can be emailed to [email protected] article was first published in the June 14-June 21, 2018 print edition of The Two River Times.last_img read more

SEA Games gives Malaysia tourism a big push

first_imgSEA Games in Calabarzon safe, secure – Solcom chief Typhoon Kammuri accelerates, gains strength en route to PH A check at the Eastin Hotel here showed scanners installed at its entrances and exits, and manned by the police.Malaysian Association of Hotel Owners vice-president Mohamad Halim Merican said such security measures were part of the Games’ security requirements.“The sporting event is good for business, especially for those hosting the athletes and delegates,” he added.Halim, who is also Seri Pacific Hotel Kuala Lumpur general mana­ger, said the hotel was at nearly 80% capacity.“Besides the athletes and delegates, their friends and families will also come to support them,” he said.ADVERTISEMENT LATEST STORIES Brace for potentially devastating typhoon approaching PH – NDRRMC Korean star Kim takes notice of PH volleybelles’ improvement MOST READ UPLB exempted from SEA Games class suspension A canopy walkway linking KL Sports City to the train station makes it accessible to sports fans.PETALING JAYA—As Malaysia rolls out the red carpet to welcome the foreign guests as it hosts the 29th SEA Games, hotels across the Klang Valley are reporting high occupancy, and some are putting in place strict security checks.Malaysian Association of Hotels (MAH) chief executive officer Yap Lip Seng said with the 12 hotels designa­ted for the Games’ participants being almost fully booked, there was a spillover as visitors had to reserve other hotels instead.ADVERTISEMENT Catriona Gray spends Thanksgiving by preparing meals for people with illnesses K-pop star Jung Joon-young convicted of gang rape, spycam crimes LOOK: Venues for 2019 SEA Games Don’t miss out on the latest news and information. PH billiards team upbeat about gold medal chances in SEA Games PLAY LIST 03:07PH billiards team upbeat about gold medal chances in SEA Games02:49World-class track facilities installed at NCC for SEA Games05:25PH boxing team determined to deliver gold medals for PH00:50Trending Articles01:35Panelo suggests discounted SEA Games tickets for students03:04Filipino athletes share their expectations for 2019 SEA Games00:45Onyok Velasco see bright future for PH boxing in Olympics02:25PH women’s volleyball team motivated to deliver in front of hometown crowd01:27Filipino athletes get grand send-off ahead of SEA Games “Big sporting events like this are a boon to everyone.“And this is much appreciated as this year has been a tough one for the industry,” he said.FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSSEA Games: Philippines picks up 1st win in men’s water poloSPORTSMalditas save PH from shutoutHe added that MAH’s 150-member hotels across the Klang Valley would be most busy from Aug 18 to 20.At some hotels, special measures have been implemented to ensure safety throughout the 12-day event, which starts on Aug 19. Malaysia Inbound Tourism Asso­cia­tion (Mita) secretary-general Adam Kamal Ahmad Kamil said tourists could face some challenges getting rooms since there was no Games Village.Despite that, he expected many from Asean countries making the bulk of the visitors.Mita, he added, had been selling special packages for the SEA Games since early this year.“Apart from the Games, there are plenty of side activities like shopping, fun at Genting Highlands and Melaka or visiting theme parks.” WATCH: Streetboys show off slick dance moves in Vhong Navarro’s wedding Read Next View commentslast_img read more

5 days agoMourinho adamant about Man Utd striker Rashford: He’s not a target man

first_imgAbout the authorFreddie TaylorShare the loveHave your say Mourinho adamant about Man Utd striker Rashford: He’s not a target manby Freddie Taylor5 days agoSend to a friendShare the loveFormer Manchester United manager Jose Mourinho is adamant Marcus Rashford is not a target man.Mourinho was speaking after Rashford scored in United’s 1-1 draw with Liverpool on Sunday.”When we beat Liverpool a couple of years ago, we played with Rashford and Romelu Lukaku up front. He is not a target man, he is a man of movement,” Mourinho told Sky Sports.”I do not think he is a pure nine. If Ole is going to play him as he did today then I think he is the perfect player for him.”He’s young but he is experienced. With 21 years he probably has more matches than some players who are 24, 25. For me he is potentially a very good player, in some models and in some positions.”As a number nine I don’t think he has the 30 goals a season in him. I don’t think he can get better as a target man. To be better as a target man is difficult for him.” last_img read more

Local Recording Artistes’ Children to Perform at ‘Kingston Reggae Night’

first_imgStory Highlights The children of several well-known local recording artistes will be afforded the opportunity to showcase their talents at the inaugural Kingston Reggae Night show, slated for the National Arena on August 5. Among the young artistes slated to perform are: Meleku Collins, son of Miguel ‘Sizzla Kalonji’ Collins; Pashion Minott, daughter of the late Lincoln ‘Sugar’ Minott; Garnett Silk Jr, son of the similarly named late top flight singer; Tony Rebel’s daughter, Davianah; and Imiru Tafari, son of Queen Ifrica, center_img The children of several well-known local recording artistes will be afforded the opportunity to showcase their talents at the inaugural Kingston Reggae Night show, slated for the National Arena on August 5.It is one of several nightly events scheduled at the Independence Festival Village at the National Stadium throughout the Emancipation/Independence period, from July 29 to August 5.Among the young artistes slated to perform are: Meleku Collins, son of Miguel “Sizzla Kalonji” Collins; Pashion Minott, daughter of the late Lincoln “Sugar” Minott; Garnett Silk Jr. son of the similarly named late top-flight singer; Tony Rebel’s daughter, Davianah; and Imiru Tafari, son of Queen Ifrica,Much is expected from these youngsters, who will be paying homage to their parents’ legacies through their performances.Patrons will also be entertained by former Third World Band member, Michael “Ibo” Cooper; Queen Ifrica; Chaka Demus; Bugle; Keznamdi; and LUST, among others.Other activities to be staged throughout the period are the Miss Jamaica Festival Queen Coronation show on August 1; Festival Fashion Flair – August 2; Mello-Go-Roun – August 3; and World Reggae Dance Championship – August 4.The Village opens at 12 noon daily, with the nightly events beginning at eight o’clock.The activities are being spearheaded by the Jamaica Cultural Development Commission under the theme: ‘Celebrating Jamaicans Home and Abroad’.last_img read more

Second Show Added – Bordello of the Damned Dinner Theatre

first_imgCome in costume or come as you are, to scrutinize evidence and figure out whodunnit while enjoying a fantastic feast.  After the murder has been solved, there will be a DJ to help us celebrate.Doors open at 6 pm, dinner and show to start at 7:00.Sponsored by the Fort St. John Curling Club, the FSJ Oil Wives, and Stage North Theatre Society. FORT ST. JOHN, B.C. – Join the Fort St. John Curling Club will hold the second night of a night of intrigue and murder March 10.  The first show on March 3 of Bordello of the Damned Murder Mystery sold-out in just days and due to demand, the Curling Club has added a second show this Saturday.Stage North Theatre Society will once again perform the dinner theatre murder mystery starting at 7 p.m.  The doors open at 6 p.m.Tickets are $65 plus fees and available at Systems Sound Source or online at Energetictickets.ca.  There are only 88 tickets available for this Saturday’s event.last_img read more