Led by graduate student Xinchen Chen, members of the Han Lab (in collaboration with researchers at the USC) have published an article in PLOS Genetics about a new CRISPR toolkit to knock out specific genes in different types of cells in fruit fly tissues, particularly focusing on the neuromuscular junction (NMJ). Using this method, researchers from the Han lab identified important genes that help maintain the NMJ structure and regulate communication between nerve and muscle...

Organ development is a robust process, resulting in a reproducible organ size and shape across organisms. Altering the rates of cell division has been shown to not affect this robustness, as cells can compensate by changing their size and shape. However, the mechanisms that control this remain unclear. Here, Isabella Burda, Adrienne Roeder and colleagues investigate this robustness in the developing Arabidopsis thaliana sepal, the leaf-like organ that encloses the flower bud, by looking at a combination of mutants that affect cell division and cell growth rate heterogeneity. Using live imaging and cell growth tracking, the authors find that, in wild-type plants and plants with an increased or decreased number of cell divisions, the organ-scale growth pattern remains unaltered....

Dr. Adrienne Roeder was featured in the latest episode of InSDB’s “Behind The Bench” interview series, where she discusses her research into the intersection of patterning and morphogenesis in Arabidopsis development, and the value of bridging the gaps between science disciplines to foster collaborative interdisciplinary...

Dr. Megan Keller, graduate of the Doerr Lab, was awarded the CHIMID Fellowship, which offers postdoctoral scholars financial and professional development support to study host-microbe interactions. The Cornell Institute of Host-Microbe Interactions and Disease (CIHMID) is composed of researchers representing multiple departments and colleges at Cornell University, united in the common pursuit of understanding host-microbe biology. This fellowship, which is supported by a National Institutes of Health training grant, encourages collaborations across multiple Cornell labs and fosters intellectual independence in research that spans various disciplines. Dr. Keller’s research will focus on repurposing antibiotics into new combinational therapy for treating clinical infections. By...

The 2024 Louisa Gross Horwitz Prize will be awarded to Scott Emr and Wesley Sundquist for discovering the ESCRT pathway and revealing how it works. Defects in ESCRT function can lead to uncontrolled cell growth and tumor formation, contributing to cancer, neurodegeneration, and Parkinson’s disease. In addition, many viruses, including HIV, hijack ESCRT machinery to exit an infected host...

In a recent paper from the Roeder lab published in Developmental Cell, Shuyao Kong and Mingyuan Zhu investigate how a mutation in the protein coding gene DRMY1 in Arabidopsis plants affects the consistent formation of sepals, which protect the flower bud. The mutation reduces protein production, leading to a disruption in signals that normally control sepal development, causing variability in their number and...

During animal development, the spatiotemporal properties of molecular events largely determine the biological outcomes. Conventional gene analysis methods lack the spatiotemporal resolution for precise dissection of developmental mechanisms. Although optogenetic tools exist for manipulating designer proteins in cultured cells, few have been successfully applied to endogenous proteins in live animals. Here, we report OptoTrap, a light-inducible clustering system for manipulating endogenous proteins of diverse sizes, subcellular locations, and functions in Drosophila. This system turns on fast, is reversible in minutes or hours, and contains variants optimized for neurons and epithelial cells. By using OptoTrap to disrupt microtubules and inhibit kinesin-1 in neurons, we show that...

Ubiquitination is a posttranslational modification in eukaryotes that plays a significant role in the infection of intracellular microbial pathogens, such as Legionella pneumophila. While the Legionella-containing vacuole (LCV) is coated with ubiquitin (Ub), it avoids recognition by autophagy adaptors. Here, we report that the Sdc and Sde families of effectors work together to build ubiquitinated species around the LCV. The Sdc effectors catalyze canonical polyubiquitination directly on host targets or on phosphoribosyl-Ub conjugated to host targets by Sde. Remarkably, Ub moieties within poly-Ub chains are either modified with a phosphoribosyl group by PDE domain-containing effectors or covalently attached to other host substrates via Sde-mediated phosphoribosyl-ubiquitination....

A new paper from the Baskin lab (in collaboration with Smolka Lab and scientists at Weill Cornell Medicine) in Nature Cell Biology reports a system for mitosis-specific protein recruitment to the plasma membrane. The work was led by graduate student Xiaofu...

Lamins are intermediate filament proteins that contribute to numerous cellular functions, including nuclear morphology and mechanical stability. The N-terminal head domain of lamin is crucial for higher order filament assembly and function, yet the effects of commonly used N-terminal tags on lamin function remain largely unexplored. Here, we systematically studied the effect of two differently sized tags on lamin A (LaA) function in a mammalian cell model engineered to allow for precise control of expression of tagged lamin proteins. Untagged, FLAG-tagged and GFP-tagged LaA completely rescued nuclear shape defects when expressed at similar levels in lamin A/C-deficient (Lmna–/–) MEFs, and all LaA constructs prevented increased nuclear envelope ruptures in these cells. N-terminal tags,...

Antimicrobial peptides (AMPs) are a promising tool with which to fight rising antibiotic resistance. However, pathogenic bacteria are equipped with several AMP defense mechanisms, whose contributions to AMP resistance are often poorly defined. Here, we evaluate the genetic determinants of resistance to an insect AMP, cecropin B, in the opportunistic pathogen Enterobacter cloacae. Single-cell analysis of E. cloacae’s response to cecropin revealed marked heterogeneity in cell survival, phenotypically reminiscent of heteroresistance (the ability of a subpopulation to grow in the presence of supra-MIC concentration of antimicrobial). The magnitude of this response was highly dependent on initial E. cloacae inoculum. We identified 3 genetic factors which collectively contribute...

This recent article from the Baskin Lab introduces a method for direct visualization of phospholipid transport mechanisms within the cell, specifically between the plasma membrane and the endoplasmic reticulum. Special fluorescent markers allowed them to study the roles of lipid transfer proteins in the interorganelle distribution of...

Roeder Lab alum Shuyao Kong has published an article in Nature Communications that investigates the role of the protein CUC1 in the relationship between developmental speed and robustness in Arabidopsis flower...

Ryan Vignogna, Postdoctoral Associate in the Fromme Lab, has been awarded the competitive NIH Ruth L. Kirschstein National Research Service Award (NRSA) Individual Postdoctoral Fellowship (F32). This fellowship, administered by the National Institutes of Health (NIH) and the National Institute of General Medical Sciences (NIGMS), supports promising researchers in pursuing postdoctoral training in biomedical, behavioral, or clinical research. As an evolutionary cell biologist, Dr. Vignogna is broadly interested in understanding how evolution shapes biological processes and how biological processes affect evolutionary outcomes. Specifically, he is interested in studying how cells respond to perturbations in conserved biological processes such as protein modifications, mitochondrial...

Roeder Lab graduate student Shuyao Kong’s recent review article in Cells and Development explores the mechanisms of developmental robustness in plants, despite cellular heterogeneity in gene expression, growth, and...

In a recent paper from the Smolka Lab, Shannon Marshall and Marcos Navarro uncover new modes of signaling via the DNA damage sensor kinase...

A publication by Brian Po-Hsun Chen (graduate student in the Baskin Lab) in the journal Nature Chemical Biology discusses new chemical tools that target a protein called oxysterol-binding protein (OSBP), which is involved in regulating cholesterol within cells and maintaining cell structure. Disruptions of OSBP function suggest a possible target in developing treatments for metabolic disease and...

In a project lead by Jeremy Keys, the Lammerding Lab published an article in the Journal of Cell Science that uncovers how cells move their large and stiff nucleus through extremely tight spaces, for example, when migrating through biological tissues. Cells contract their rear to generate hydrostatic pressure that pushes the nucleus through the constriction, but use a pulling mechanism when migrating through unconfined...

How does DNA damage signaling suppress chromosomal rearrangements? Check out recent paper spearheaded by Smolka Lab graduate research assistant Bokun Xie, just out in EMBO Journal. Multi-step control of homologous recombination via Mec1/ATR suppresses chromosomal rearrangements....

The Mec1/ATR kinase is crucial for genome stability, yet the mechanism by which it prevents gross chromosomal rearrangements (GCRs) remains unknown. Here we find that in cells with deficient Mec1 signaling, GCRs accumulate due to the deregulation of multiple steps in homologous recombination (HR). Mec1 primarily suppresses GCRs through its role in activating the canonical checkpoint kinase Rad53, which ensures the proper control of DNA end resection. Upon loss of Rad53 signaling and resection control, Mec1 becomes hyperactivated and triggers a salvage pathway in which the Sgs1 helicase is recruited to sites of DNA lesions via the 911-Dpb11 scaffolds and phosphorylated by Mec1 to favor heteroduplex rejection and limit HR-driven GCR accumulation. Fusing an ssDNA recognition domain to Sgs1...