Watching HIV Bud from Cells

Study Shows Last-Minute Role of Protein Named ALIX

University of Utah physics doctoral student Pei-I Ku prepares a sample for the digital microscope she uses to make movies and photographs of the AIDS-causing human immunodeficiency virus budding from human cells in the laboratory. The microscope is in a glass chamber to keep the cells at body temperature so researchers can watch the process over time. Ku is the first author of a new study in which University of Utah researchers combined imaging technology and biochemistry to make such images. The method revealed that a protein named ALIX gets involved in the process later than believed previously. Photo Credit: Tom Bear ( for the University of Uta

May 16, 2014 – University of Utah researchers devised a way to watch newly forming AIDS virus particles emerging or “budding” from infected human cells without interfering with the process. The method shows a protein named ALIX gets involved during the final stages of virus replication, not earlier, as was believed previously.

“We watch one cell at a time” and use a digital camera and special microscope to make movies and photos of the budding process, says virologist Saveez Saffarian, an assistant professor of physics and astronomy and senior author of a new study of HIV budding published online today in the Public Library of Science journal PLOS ONE.

“We saw ALIX recruited into HIV budding for the first time,” he says. “Everybody knew ALIX is involved in HIV budding, but nobody could visualize the recruitment of ALIX into the process.”

The finding is “fundamental basic science” and has no immediate clinical significance for AIDS patients because ALIX is involved in too many critical functions like cell division to be a likely target for new medications, Saffarian says.

“We know a lot about the proteins that help HIV get out of the cell, but we do not know how they come together to help the virus get out, and it will be in the next 10 to 20 years that we will know a lot more of about this mechanism,” he adds. “Would this be a drug target? Would this be a part of biochemistry used in a therapeutic or biotech industry later on? I can’t tell you now. But if it was not because of our curiosity as a species, we would not have the technology we have today.”

The new study “is nice work,” says HIV budding expert Wes Sundquist, who advised Saffarian and is professor and co-chair of biochemistry at the University of Utah School of Medicine. “It’s of genuine interest for those of us who study the mechanism of HIV assembly.”

The study was funded by the National Science Foundation. Saffarian conducted the study with first author, Pei-I Ku, a University of Utah doctoral student in physics; Mourad Bendjennat, a postdoctoral research associate in physics and astronomy; technician Jeff Ballew; and Michael Landesman, another postdoctoral fellow in physics and astronomy who previously worked in Sundquist’s biochemistry lab.

Full Press Release.


Nearest Bright ‘Hypervelocity Star’ Found

Speeding at 1 Million mph, It Probes Black Hole and Dark Matter

An astrophysicist-artist's conception of a hypervelocity star speeding away from the visible part of a spiral galaxy like our Milky Way and into the invisible halo of mysterious "dark matter" that surrounds the galaxy's visible portions. University of Utah researcher Zheng Zheng and colleagues in the U.S. and China discovered the closest bright hypervelocity star yet found. Photo Credit: Ben Bromley, University of Utah

May 7, 2014 – A University of Utah-led team discovered a “hypervelocity star” that is the closest, second-brightest and among the largest of 20 found so far. Speeding at more than 1 million mph, the star may provide clues about the supermassive black hole at the center of our Milky Way and the halo of mysterious “dark matter” surrounding the galaxy, astronomers say.

“The hypervelocity star tells us a lot about our galaxy – especially its center and the dark matter halo,” says Zheng Zheng, an assistant professor of physics and astronomy and lead author of the study published recently in Astrophysical Journal Letters by a team of U.S. and Chinese astronomers.

“We can’t see the dark matter halo, but its gravity acts on the star,” Zheng says. “We gain insight from the star’s trajectory and velocity, which are affected by gravity from different parts of our galaxy.”

In the past decade, astronomers have found about 20 of these odd stars. Hypervelocity stars appear to be remaining pairs of binary stars that once orbited each other and got too close to the supermassive black hole at the galaxy’s center. Intense gravity from the black hole – which has the mass of 4 million stars like our sun – captures one star so it orbits the hole closely, and slingshots the other on a trajectory headed beyond the galaxy.

Zheng Zheng, an assistant professor of physics and astronomy at the University of Utah, led a team of American and Chinese scientists who discovered the closest bright hypervelocity star of 20 yet found. Scientists believe each hypervelocity star began as part of a binary pair of stars near the center of our Milky Way galaxy, where extreme gravity from a supermassive black hole sucked in one star in the pair and, like a bolo, simultaneously hurled the other star -- a new hypervelocity star -- toward the edge of the galaxy. Photo Credit: Lee J. Siegel, University of Utah

Zheng and his colleagues discovered the new hypervelocity star while conducting other research into stars with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, or LAMOST, located at the Xinglong Observing Station of the National Astronomical Observatories of China, about 110 miles northeast of Beijing.

LAMOST boasts a 13.1-foot-wide aperture and houses 4,000 optical fibers, which capture “spectra” or light-wavelength readings from as many as 4,000 stars at once. A star’s spectrum reveals information about its velocity, temperature, luminosity and size.

LAMOST’s main purpose is to study the distribution of stars in the Milky Way, and thus the galaxy’s structure. The new hypervelocity star – named LAMOST-HVS1 – stood out because its speed is almost three times the usual star’s 500,000-mph pace through space: 1.4 million mph relative to our solar system. Its speed is about 1.1 million mph relative to the speed of the center of the Milky Way.

Despite being the closest hypervelocity star, it nonetheless is 249 quadrillion miles from Earth. (In U.S. usage, a quadrillion is 1,000,000,000,000,000 miles or 10 to the 15th power, or 1 million billion).

“If you’re looking at a herd of cows, and one starts going 60 mph, that’s telling you something important,” says Ben Bromley, a University of Utah physics and astronomy professor who was not involved with Zheng’s study. “You may not know at first what that is. But for hypervelocity stars, one of their mysteries is where they come from – and the massive black hole in our galaxy is implicated.”

Full Press Release


Astronomy Week

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Monday, May 5:
Telescopes in the Park, Solar Observing at Liberty Park,
Noon - 4:00 pm

Join the University of Utah's AstronomUr Outreach Group at Liberty Park to view the Sun through specialized telescopes! Learn more...

Tuesday, May 6:
Sidewalk Solar Observing Party, Downtown City Library
Noon - 4:00 pm

Think star-gazing is only possible at night? Think again! Join us at the City Library in downtown Salt Lake for solar observing. Learn more...

Wednesday, May 7:
Star Party & Solar Observing at the South Physics Observatory 
6:00 pm - 11:00 pm

Let our observatory guides take you on a tour of the night sky! Learn more...

Thursday, May 8:
Film Festival with Topical Discussions, 408 South Physics Building, University of Utah
6:00 pm - 8:00 pm

Join our AstronomUrs in a cosmic journey Hollywood-style and learn why space is so hard to replicate on the big screen! Learn more...

Friday, May 9:
Star Party at the South Physics Observatory, University of Utah
8:00 pm - Midnight

Come explore astronomy through one of our 14 telescopes and learn how astronomers make discoveries! Learn more...

Saturday, May 10:
Astronomy Activities at the Natural History Museum of Utah,
Noon - 4:00 pm

Learn more about telescopes and how astronomers make discoveries with a variety of presentations and activities! Learn more...


2014 Graduation Awards & Scholarships

Graduation and commencement exercises for the University of Utah took place on May 1-2, 2014. The Department of Physics & Astronomy congratulates all of its 2014 graduates and welcomes them to their alumni family.

Anne Marie Schaeffer

Weili Hong

Uyen Huynh

Hans Malissa

Dali Sun

Christopher Ahn

Ian Sohl

Joshua Wallace

Rachel Baarda

Alissa Whiting

Julie Imig

Ethan Lake

Congratulations to our 2014 graduates and scholarship recipients!

2014 Awards & ScholarshipsBaccalaureate DegreesMasters DegreesPh. D Degrees

Swigart Scholarship for Outstanding Graduate Student
Anne Marie Schaeffer
Weili Hong
Henrik Odeen

Outstanding Graduate Student
Mark Limes
Uyen Huynh

Outstanding Postdoctoral Research
Hans Malissa
Dali Sun

Outstanding Graduate Teaching Assistants
Chris Ahn
Janivda Rou

Outstanding Undergraduate Teaching Assistants
James Skowronek

Paul Gilbert Outstanding Undergraduate Research
Joshua Wallace

Martin Hiatt Outstanding Undergraduate Research
Rachel Baarda

Outstanding Undergraduate - Senior
Leslie Mershon

Outstanding Undergraduate - Junior
Trey Jensen

Outstanding Undergraduate - Sophomore
Alissa Whiting

Walter Wada Memorial Award
Julie Imig

Tyler Soelberg Memorial Award
Josh Hanes

Parmley Award
Ian Sohl

Departmental Scholarship
Christopher Harker
Trey Jensen
Ethan Lake
David Stephens

Rachel Baards – HBS
Kouver Bingham – HBS
Matthew Byrne
Zachary Carson
Andrew Dilts
Parker Duncan
Tristan Ellsworth
Mohamed Elsherif – Physics Teaching
Anthony Garcia - HBS
Chris Ginzton – BA
Nathan Gygi
Laurel Hales - HBS
Nino Hodzic
Erik Houghtby
Matthew Hunsaker
Natascha Knowlton
Austin Lee
Kayla Martindale
Shawn Merrill
Quinton Nethercott
Jeff Palmer
Evangelia Papadopoulos – HBS
Tyler Schmauch
Justin Talbot
Scott Temple
Sean Vetsch
Joshua Wallace – HBS
Matthew Wallace
Joshua Wolfe
Veronika Burobina
Michael Doleac – Physics Teaching
David Harris
Brendan Pankovich
Weili Hong
Mark Limes
Robert Roundy
Yiping Shu
Xuefang Sui
Alex Thiessen
David Waters
Rhett Zollinger


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