A5028531723- Cellular Mechanics and Interactions
- Microtubule and mitosis dynamics
- Hearing, Cochlea, Tinnitus, Genetics
- RNA Research and Splicing
- Cell Adhesion Molecules Research
- Cardiomyopathy and Myosin Studies
- Muscle Physiology and Disorders
- Cellular transport and secretion
- Ubiquitin and proteasome pathways
- Mitochondrial Function and Pathology
- Microfluidic and Bio-sensing Technologies
- RNA modifications and cancer
- Advanced Fluorescence Microscopy Techniques
- interferon and immune responses
- ATP Synthase and ATPases Research
- Biotin and Related Studies
- Cell Image Analysis Techniques
- Extracellular vesicles in disease
- Microbial Metabolism and Applications
- Endoplasmic Reticulum Stress and Disease
- Cancer-related gene regulation
- Protein Kinase Regulation and GTPase Signaling
- Toxoplasma gondii Research Studies
- RNA and protein synthesis mechanisms
- Skin and Cellular Biology Research
National Institute on Deafness and Other Communication Disorders
2015-2025
National Institutes of Health
2015-2025
Laboratory of Molecular Genetics
2020
Massachusetts Institute of Technology
2007-2015
University of Virginia
2005
National Center for Biotechnology
2001
Ena/VASP proteins influence the organization of actin filament networks within lamellipodia and filopodia migrating cells in comet tails. The molecular mechanisms by which control dynamics are unknown. We investigated how regulate polymerization at barbed ends vitro presence absence end capping proteins. Recombinant His-tagged VASP increased rate cappers, heterodimeric protein (CP), CapG, gelsolin-actin complex. Profilin enhanced ability to protect from CP, this required interactions...
Filopodia have been implicated in a number of diverse cellular processes including growth-cone path finding, wound healing, and metastasis. The Ena/VASP family proteins has emerged as key to filopodia formation but the exact mechanism for how they function yet be fully elucidated. Using cell spreading model system combination with small interfering RNA depletion Capping Protein, we determined that role beyond anticapping activity formation. Analysis mutant demonstrated entire EVH2 domain was...
Hair cells, the mechanosensory receptors of inner ear, are responsible for hearing and balance. cell death consequent loss common results treatment with ototoxic drugs, including widely used aminoglycoside antibiotics. Induction heat shock proteins (HSPs) confers protection against aminoglycoside-induced hair via paracrine signaling that requires extracellular 70-kDa protein (HSP70). We investigated mechanisms underlying this non–cell-autonomous protective in ear. In response to stress, ear...
Assembly of actin-based stereocilia is critical for cochlear hair cells to detect sound. To tune their mechanosensivity, form bundles composed graded rows ascending height, necessitating the precise control actin polymerization. Myosin 15 (MYO15A) drives bundle development by delivering proteins growing that regulate polymerization via an unknown mechanism. Here, we show MYO15A itself nucleation-promoting factor. Moreover, a deafness-causing mutation in actin-binding interface inhibits...
Filopodia are long plasma membrane extensions involved in the formation of adhesive, contractile, and protrusive actin-based structures spreading migrating cells. Whether filopodia formed by different molecular mechanisms equally support these cellular functions is unresolved. We used Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP)-deficient MV(D7) fibroblasts, which also devoid endogenous mDia2, as a model system to investigate how actin regulatory proteins affect morphology...
Abstract The maintenance of sensory hair cell stereocilia is critical for lifelong hearing; however, mechanisms structural homeostasis remain poorly understood. Conflicting models propose that F-actin cores are either continually renewed every 24–48 h via a treadmill or stable, exceptionally long-lived structures. Here to distinguish between these models, we perform an unbiased survey actin dynamics in more than 500 utricle cells. Live-imaging EGFP-β-actin dendra2-β-actin reveal stable with...
Human mitochondrial RNase P (mt-RNase P) is responsible for 5' end processing of precursor tRNAs, a vital step in RNA maturation, and comprised three protein subunits: TRMT10C, SDR5C1 (HSD10), PRORP. Pathogenic variants TRMT10C are associated with distinct recessive or x-linked infantile onset disorders, resulting from defects processing. We report four unrelated families multisystem disease bi-allelic PRORP, the metallonuclease subunit mt-RNase P. Affected individuals presented variable...
Stereocilia on auditory sensory cells are actin-based protrusions that mechanotransduce sound into an electrical signal. These stereocilia arranged a bundle with three rows of increasing length to form staircase-like morphology is required for hearing. in the shorter rows, but not tallest row, mechanotransducing because they have force-sensitive channels localized at their tips. The onset mechanotransduction during mouse postnatal development refines and width. However, it unclear how actin...
Chemotaxis regulates the recruitment of leukocytes, which is integral for a number biological processes and mediated through interaction chemokines with seven transmembrane G-protein-coupled receptors. Several studies have indicated that chemotactic signaling pathways might be activated via G-protein-independent mechanisms, perhaps novel receptor-interacting proteins. CXCR2 major chemokine receptor expressed on neutrophils. We used proteomics approach to identify unique ligand-dependent...
Protein–protein interactions (PPIs) regulate assembly of macromolecular complexes, yet remain challenging to study within the native cytoplasm where they normally exert their biological effect. Here we miniaturize concept affinity pulldown, a gold-standard in vitro PPI interrogation technique, perform nanoscale pulldowns (NanoSPDs) living cells. NanoSPD hijacks normal process intracellular trafficking by myosin motors forcibly pull fluorescently tagged protein complexes along filopodial...
The facultative intracellular human pathogenic bacterium <i>Listeria monocytogenes</i> actively recruits host actin to its surface achieve motility within infected cells. bacterial protein ActA is solely responsible for this process by mimicking fundamental steps of cell dynamics. ActA, a modular protein, contains an N-terminal nucleation site and central proline-rich motif the 4-fold repeated consensus sequence FPPPP (FP<sub>4</sub>). This specifically recognized members Ena/VASP family....
Sound localization requires extremely precise development of auditory brainstem circuits, the molecular mechanisms which are largely unknown. We previously demonstrated a novel requirement for non-apoptotic activity protease caspase-3 in chick development. Here, we used mass spectrometry to identify proteolytic substrates during Functional annotation analysis revealed that our were enriched more than two-fold proteins associated with extracellular vesicles (EVs), membrane-bound nanoparticles...
The members of the actin regulatory family Ena/VASP proteins form stable tetramers. vertebrate family, VASP, Mena and EVL, have many overlapping properties expression patterns, but functional differences between paralogues been observed. formation mixed oligomers may serve a role to refine activity. While it has assumed that can oligomers, this possibility not investigated systematically. Using cells expressing controlled combinations we evaluated composition found VASP forms without...
SUMMARY The assembly and maintenance of actin-based mechanosensitive stereocilia in the cochlea is critical for lifelong hearing. Myosin-15 (MYO15) hypothesized to modulate height by trafficking actin regulatory proteins their tip compartments, where polymerization must be precisely controlled during development. We identified a mutation (p.D1647G) MYO15 motor-domain that initially maintained trafficking, but caused progressive hearing loss stunting growth, revealing an additional function...
The mitoribosome synthesizes 13 protein subunits of the oxidative phosphorylation system encoded by mitochondrial genome. is composed 12S rRNA, 16S rRNA and 82 mitoribosomal proteins nuclear genes. To date, variants in 12 genes encoding are associated with rare monogenic disorders, frequently show combined deficiency. Here, we describe five unrelated individuals biallelic
The mitochondrial ribosome (mitoribosome) synthesizes 13 protein subunits of the oxidative phosphorylation system encoded by genome. mitoribosome is composed 12S rRNA, 16S and 82 mitoribosomal proteins nuclear genes. To date, variants in 12 genes encoding are associated with rare monogenic disorders frequently show combined deficiency. Here, we describe five unrelated individuals bi-allelic death-associated 3 (DAP3), a gene small subunit 29 (MRPS29), variable clinical presentations ranging...
Abstract Perrault syndrome is a rare autosomal recessive condition characterised by sensorineural hearing loss in both sexes and primary ovarian insufficiency 46 XX, females. It genetically heterogeneous with biallelic variants six genes identified to date ( HSD17B4 , HARS2 LARS2 CLPP C10orf2 ERAL1 ). Most possessing associated are involved mitochondrial translation. We describe consanguineous family three affected individuals homozygous for novel missense variant c.1454C>T; p.(Ala485Val)...
The mouse utricle model system is the best-characterized ex vivo preparation for studies of mature mammalian hair cells (HCs). Despite many advantages this system, efficient and reliable quantification HCs from cultured utricles has been a persistent challenge with system. Utricular are commonly quantified by counting immunolabeled in regions interest (ROIs) placed over an image utricle. Our data indicate that accuracy HC counts obtained using method can be impacted variability density...
Myosin 18Aα is a myosin 2-like protein containing unique N- and C-terminal interaction domains that co-assembles with 2. One known to bind β-Pix, guanine nucleotide exchange factor (GEF) for Rac1 Cdc42 has been shown promote dendritic spine maturation by activating the assembly of actin filaments in spines. Here, we show 18A⍺ concentrates spines cerebellar Purkinje neurons via co-assembly 2 through an binding site its N-terminal extension. miRNA-mediated knockdown results significant defect...
SUMMARY Protein-protein interactions (PPIs) regulate signal transduction and cellular behavior, yet studying PPIs within live cells remains fundamentally challenging. We have miniaturized the affinity pulldown, a gold-standard PPI interrogation technique, for use cells. Our assay hijacks endogenous myosin motors to forcibly traffic, or macromolecular complexes native cytosolic environment. Macromolecules captured by nanoscale pulldown (NanoSPD) are optically interrogated in situ tagging...
Proteins of the Homer/Vesl family are enriched at excitatory synapses and selectively bind to a proline-rich consensus sequence in group 1 metabotropic glutamate receptors via domain that shows strong similarity Ena/VASP homology (EVH1) domains. EVH1 domains play an important role actin cytoskeleton dynamics. Crystals murine Vesl-2b were obtained diffract X-rays 2.4 Å resolution. They belong space C2, with unit-cell parameters = 112.8, b 69.9, c 54.9 Å, β 110.7°, consistent three molecules...