UT Southwestern Medical Center

WEAVER LAB
UT SOUTHWESTERN MEDICAL CENTER
DEPARTMENT of PHARMACOLOGY
Caspases and Proteolytic Mechanisms
Mediating Cell Fate, Signaling and Gene Expression Dynamics
Evidence across diverse phyla of metazoans depicts a new landscape for proteolytic factors, such as caspases, as not only effectors but key regulators of many cellular processes. In particular, genetic masking has hitherto limited our ability to observe many so-called "non-canonical" caspase functions that our work has recently brought to light. Now is an exciting time to be part of this rapidly emerging field.
The over-arching theme of the Weaver Lab is to deeply understand how proteolytic factors mediate diverse physiological functions. Along those lines, we have identified CED-3 caspase working to support a variety of cellular functions ranging from limiting symmetric divisions of a stem-like cell type during cell fate decisions to opposing p38 MAPK stress signaling and downstream gene expression program to promote development. We find that caspases often work with other regulatory pathways to achieve their non-canonical functions. Current lines of inquiry include: (1) how a given caspase is able to distinguish cell death from cell vigor substrates, (2) how proteolytic factors sculpt gene expression dynamics and (3) what upstream inputs license one proteolytic function over another.
To tackle these and other challenging questions, we employ a cross-disciplinary approach including genetics, proteomics and biophysical analyses. The Weaver lab utilizes C. elegans, mammalian cell culture, and biochemical models. Equipped with powerful tools, we are setting out to understand how proteolytic factors execute a potentially vast array of functions.
PEOPLE

DR. BENJAMIN WEAVER
Principal Investigator

DR. YI MIAO WEAVER
Sr. Research Scientist
Structure function studies of proteolytic factors

DR. WANG YUAN
Post-Doctoral Researcher
Roles of caspases and p38 MAPK in development

DR. HAI WEI
Post-Doctoral Researcher
Caspases in stress responses

FRANCISCO CALVA MORENO
MSTP Graduate Student
Ph.D. Candidate
UBR E3 ligases in development and disease

WE ARE STILL RECRUITING!!
Grad Student applicants: Apply through the umbrella program and send Ben an email.
Post-Doc and Technician applicants: email Ben with your letter of interest.
RESEARCH
Current Priorities and Training Environment
The Weaver lab is interdisciplinary and employs state of the art genetic, biochemical, proteomic, transcriptomic, and biophysical approaches to analyze dynamic processes such as development, aging and stress responses. Using C elegans, mammalian cell culture, and in vitro models, our goal is to understand how proteolytic factors regulate critical cellular life or death decisions. Understanding the regulatory mechanisms of such decisions has broad impact on a variety of disease etiologies including cancers, degenerative diseases, and developmental disorders. Trainees joining the Weaver lab at UT Southwestern Medical Center will learn cutting-edge methodologies in diverse disciplines. Although highly interactive, members of the Weaver lab each have distinct projects developed with significant mentoring. This model allows each of us to focus on an exciting aspect of the larger whole. Our lab has a track-record of tackling fundamental biological processes from the level of phenotypes down to molecular mechanisms. We have an array of ongoing studies with several areas of emphasis indicated below.

CELL SIGNALING
We recently unmasked a broad array of genes working with caspase outside of cell death. Using proteomic, genetic, and cell biological approaches, we are probing the network and mechanisms of caspases in sculpting cell signaling.
GENE EXPRESSION DYNAMICS
We recently showed CED-3 caspase and PMK-1 p38 MAPK balancing stress-responsive and developmental functions. We are using a big data approach including genomics, proteomics, and translatomics to understand how broadly caspases and p38 MAPKs act in gene expression dynamics.


CELL FATE
Using genetic, biochemical, and genomic approaches we demonstrated a non-canonical caspase function working in parallel to the miRISC pathway was critical to ensure temporal cell fate patterning limiting symmetric cell divisions at a critical developmental window. We are expanding these studies to understand the roles of proteolytic factors in mediating cell fate decisions.
STRESS RESPONSES
Throughout metazoans, caspases have been assoicated with stress responses. We recently showed how CED-3 caspase antagonizes activation of a pathogen response. We are using advanced CRISPR methods combined with omic approaches and advanced cell imaging to understand how developmental and stress-responsive states are dynamically regulated.


DIFFERENTIAL REGULATION
Across nematodes, flies, and mammals, classic cell death caspases have been found with critical non-canonical functions supporting cell vigor. We are using genetic and biochemical methods to understand how a given caspase with both cell death and cell vigor functions is differentially regulated.
SUBSTRATE RECOGNITION
We recently showed that the CED-3 caspase required a UBR-type E3 ubiquitin ligase to efficiently cleave and degrade LIN-28 in vivo. We further showed that the caspase and E3 ligase may form a complex. We are using biochemical and biophysical methods to understand how proteolytic factors recognize distinct substrates to achieve diverse functions.

SELECTED PUBLICATIONS
2020
Non-Canonical Caspase Activity Antagonizes p38 MAPK Stress-Priming Function to Support Development
Weaver BP, Weaver YM, Omi S, Yuan W, Ewbank JE, Han M Dev Cell 53(3): 358-369
Featured in Development or Disease: Caspases Balance Growth and Immunity in C. elegans
Olya Yarychkivska and Shai Shaham Dev Cell 53(3): 259-260
2018
Tag team: Roles of miRNAs and Proteolytic Regulators in Ensuring Robust Gene Expression Dynamics.
Weaver BP, Han M Trends Genet. 34(1):21-29
2017
Coupled Caspase and N-End Rule Ligase Activities Allow Recognition and Degradation of Pluripotency Factor LIN-28 during Non-Apoptotic Development.
Weaver BP, Weaver YM, Mitani S, Han M Dev. Cell 41(6):665-673
Featured in Partners in Crime
Barbara Conradt Dev Cell 41(6): 573-574
2016
Time to move the fat.
Weaver BP, Sewell AK, Han M Genes Dev. 30(13):1481-1482
2014
CED-3 caspase acts with miRNAs to regulate non-apoptotic gene expression dynamics for robust development in C. elegans.
Weaver BP, Zabinsky R, Weaver YM, Lee ES, Xue D, Han M eLife e04265
Featured in Development: Cell Death Machinery Makes Life More Robust
Cristina Aguirre-Chen and Christopher M Hammell eLife 3:e05816
Also featured in For Caspases, An Escape from Death
Beverly A Purnell Science 347(6218): 142-143
LAB NEWS
March 2022
Wang's first author paper out for peer review!
May 2021
Francisco passed his qualifying exams!
March 2021
Wang wins the Weaver Lab Spring Pretty Gel Competition!
February 2020
Dr. Hai Wei joins the lab for post-doctoral studies!
November 2019
Francisco Calva Moreno joins the lab for graduate studies!
July 2019
Ben's MIRA grant funded through NIGMS!
May 2019
Dr. Wang Yuan joins the lab for post-doctoral studies!
April 2019
Ben's Welch Foundation grant funded!
September 2018
Weaver Lab established!
Ben and Yi get to work in the Department of Pharmacology at UT Southwestern Medical Center. Our central goals are to unravel how proteolytic factors impact diverse physiological outcomes and how these divergent functions are regulated.
Post-Doc Years
While working in Min Han's HHMI lab at CU Boulder, we discovered a non-canonical function for CED-3 caspase in limiting supernumerary cell divisions of an epidermal stem-like cell type in C. elegans. We also found that CED-3 caspase required a UBR-type E3 ubiquitin ligase from the Arg/N-end rule to efficiently proteolytically cleave the non-apoptotic target LIN-28 in vivo.
GALLERY
FUN
Food for Thought
Not too surprisingly, biochemistry was born out of early efforts to perfect the enzymology and chemistry behind the fermentation of grains, fruits and milk to generate the varieties of dough, beer, wine and cheese that we know today from around the globe. Here are a few glimpses of having some fun experimenting outside the lab.

TRADITIONAL PIE of CHINA by HAI
Power-packed gems filled with pork and cabbage. Seasoned with salt, soy sauce, oil, garlic, ginger, and green onion. Hai’s pro-tip: Make the outside bun with fermented dough. After lightly frying, pop these little party favorites into the oven for a crispy baked finish you won’t soon forget!

BEEF RAMEN NOODLES by YI
Fusion of ramen noodles seasoned lightly with onion and parsley for a hearty combo. Yi’s top-shelf ingredients…Tie this simple masterpiece together with Napa cabbage boiled in a soy-based broth. Add wood-smoked beef slices on top for a simple but super-delicious meal!

FAJITAS by FRANCISCO
Visually stunning arrangement of fajitas served with guacamole, beans, pico de galla and rice.
That’s not all! Francisco threw in a loaf of baked banana bread for a super-satisfying finish!

HOT POT by WANG
Traditional Chinese sensation that begins with a spicy soup stock and an assortment of meats, veggies, starchy noodles and you’re ready to roll! Wang's philosophy: best part is that you can add anything, this dish knows no limits! What more could you ask for?

NON-CANONICAL BARBECUE by BEN
Savory homemade marinades with thyme, cumin and bay leaf combined with hickory and cherry wood smoke for a decadent, savory flavor. How to plate? Ben likes to serve up his BBQ with grilled asparagus and homemade potato salad.

Hai joins the lab, New Years 2020!!!
Sorry Wang and Francisco...
We forgot to take pictures of your celebrations.
Oops
CONTACT
Interested in joining? We would love to hear from you.
benjamin.weaver [at] utsouthwestern.edu
This website reflects only the views of the author and is not a publication of UT Southwestern, which bears no responsibility for its content.
UT Southwestern Medical Center
Pharmacology
6001 Forest Park Rd
Dallas, TX 75390
USA
