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Lab Personnel


David Costantino, M.S., HHMI Lab Manager

”In my role as lab manager I am responsible for much of the day to day operation, but I also get to do research, which is the main reason I am so excited ​to be part of this g​roup. When people ask me what I do for a living, I tell them I can save the crickets, and that is always a great way to introduce what we study in our lab.”

David likes donuts…with sprinkles. He also plays tennis, eats BBQ and Italian food, loves baseball, plays poker, goes to lots of hockey games, and teaches chess to school kids. Scouting reports describe him as a fantasy sport force to be reckoned with whenever he steps on the field.


Tim Colussi, Ph.D., Postdoctoral Fellow

“Many new functions for tRNA have been discovered outside of the commonly known function of linking mRNA and protein synthesis. Many viruses encode various tRNA mimics, whose function still remain a mystery. My research focuses on studying the structural and functional aspects of these tRNA mimics to help elucidate the role they play in the virus life cycle.”

It takes a real man to wear a pink bowling shirt. In addition to bowling, Tim also likes Ultimate Frisbee and other outdoor sports, and brews beers that compete at a national level. He has discovered that snowboarding in Colorado is different than it is in North Carolina.


 

Terra-Dawn Plank, Graduate Student (Molecular Biology)
Completed American Heart Association Predoctoral Fellowship
and Microbiology T32 training grant appointment

“The HIV-1 life-cycle is largely driven by interactions between the 5’ RNA leader and host cell proteins. My project focuses on understanding how the HIV-1 leader uses host cell proteins for synthesis of its viral proteins. Our studies suggest that HIV-1 may co-opt host cell proteins to allow for protein synthesis from an internal ribosome entry site (IRES), and that translation from this IRES may be regulated by specific RNA sequences to allow for highly regulated viral protein expression. What’s cool about my project is that I get to utilize many new and informative techniques in the lab to better understand how HIV-1 makes its proteins. The unique RNA-protein interactions I identify in my studies may lead to the development of new therapeutic targets in the treatment of HIV-1.”

Terra rarely sports a mustache. She appreciates good food and good drink, and likes to be outside: she plays kickball, runs (training for a marathon), and snowboards. She also plays in the campus orchestra.


Yumeng Hao, Graduate Student (Molecular Biology)
Currently an American Heart Association Predoctoral Fellow

“My project focuses on a RNA molecule in a bacteriophage packaging motor. During viral assembly, the phi29 bacteriophage uses a powerful packaging motor to package its 19.3 kb DNA genome into the capsid in less than five minutes and the packaging process is under tremendous back-pressure, around 79pN, which is roughly ten times the pressure in a champagne bottle. However, no one really understands how this awesome motor works. Currently, I use biochemical and biophysical methods to characterize the pRNA, which is an important component of the motor, understand its role and how it interacts with other components to package the genome.”

“What-is-up?” Yumeng arrived in the U.S. and jumped right into research with a vengeance. She’s got an artistic flair (origami, drawing), she likes Kung Fu Panda (and other cartoons), traveling, and judging from this photo, Renaissance fairs as well. “Have a good one.”


Marisa Ruehle, Graduate Student (Molecular Biology)
Completed Molecular Biology T32 training grant appointment
Currently an American Heart Association Predoctoral Fellow

“My project in the Kieft Lab focuses on understanding how the IGR IRESs initiate protein synthesis. The IGR IRESs accomplish internal initiation solely through their compact tertiary fold, and we hypothesize that this induces structural changes in the ribosome and tRNA that essentially “trick” them into proceeding to the elongation phase of translation. I think it is so cool how this one 200 nucleotide RNA can manipulate a huge molecular machine simply through changes in structure and conformational dynamics. Furthermore, the IGR IRESs give us a window into the basic principles of ribosome function by allowing us to study how viruses have evolved to hijack this important cellular machine for their own purposes.”

Marisa has great hair, but only sports this ‘do on Fridays. She also plays volleyball, likes to cook, skis (telemark – you should be impressed), hikes, and loves the Colorado outdoors.




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Zane Jaafar, Graduate Student (Microbiology)

“My interests in the Kieft lab are in understanding the interplay between Hepatitis C virus (HCV) RNA biology and cellular stress responses. Specifically, I aim to study the manner in which the HCV internal ribosome entry site (IRES) is able to maintain its capacity for translation during infection-induced cellular stress-response programs. I intend to add to a growing body of research that is bridging the gap between RNA structural biology and RNA virology.”

Zane is the newbie, and much smarter than this picture might suggest. Then again, he does skydive a lot, which could bring his smarts into question. Zane finds humor in odd things, which we find funny, which he thinks is amusing.




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Erich Chapman, PhD., Postdoctoral Fellow

“Dengue, West Nile and Yellow Fever are all caused by viruses from the Flavivirus family. It’s recently been discovered that a relatively short, subgenomic RNA plays an important role in the lifecycle of these viruses. This ¬short flaviviral RNA (sfRNA) is produced by limited degradation of the viral genome by the host-cell exonuclease Xrn1. Xrn1 is a conserved, highly processive 5’à3’ exonuclease and is a critical component of RNA metabolism in eukaryotic cells. This exonuclease proceeds through over 10kb of flaviviral RNA before becoming stalled at one of several conserved secondary structures present in the 3’ untranslated region of each flaviviral genome. My mission is to dissect the biophysical properties that confer Xrn1-resistance to these RNAs and to ultimately leverage this understanding into a treatment for disease.”

None of us are sure what Erich was doing in this picture, but it looks pretty manly. Erich wears Carhartts, eats tofu and sometimes misses the North. He likes poetry slams, most tempranillos, helicopters, yoga and deep deep snow. And of course… RNA!


Brian Wimberly, PhD., HHMI Research Specialist

Brian wants to push the frontiers of structural biology. Beyond that, you aren’t getting any more information out of him, so don’t even try.

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Megan Filbin, PhD., Post-doctoral Fellow, Janelia Farm Visitors Program

“I am studying how ribosomes – large machines inside our cells that make proteins – can be controlled or manipulated by our cells. I am curious whether cells alter ribosomes depending upon where they are located within the cell, much like we alter the type of tires on our cars depending on the terrain. In doing so, the cell may be directing ribosomes to make certain proteins, to function during certain times in the cell’s life or some combination thereof.”

Meg is back after a year of high adventure at Janelia Farm in Virginia. She learned about cryo-EM, membrane proteins, neurons, and how awful it is to be away from Broncos Fans. She still smiles a lot, and says stuff like “peace out, trout!”

 



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​Erica Eyer, Administrative Assistant

Reimbursements, travel, scheduling… you name it! Erica keeps everything straight because goodness knows we can’t count on Jeff for that.

 

​Erik Hartwick, Graduate Student (Structural Biology and Biochemistry)

“RNA “working” RNA—I’m studying how structured RNA virus elements manipulate the ribosome, an RNA-based machine. Many viruses have evolved ways to commandeer host cell ribosomes and initiate protein synthesis in a streamlined mechanism compared to normal eukaryotic translation. Unique viral RNA structural elements, known as an IRES, drive this streamlined mechanism of protein synthesis in the absence of initiation factors, capped and polyadenylated mRNAs.  It is my goal to understand what a viral IRES RNA-bound ribosome structure looks like at the atomic resolution and how these small RNA structures biophysically engage the ribosome. I think this is exceptionally rad because it is an example of two non-coding RNAs interacting in a structurally dynamic way to drive efficient protein synthesis...mind blown.”

Erik is an official “tough mudder,” rock climber, beer drinker, and lover of all things outdoors. He wants to crystallize big stuff. Any visual similiarity to “groundskeeper Willie” is mereley superficial.