R D Goldman

Northwestern University, Evanston, Illinois, United States

Are you R D Goldman?

Claim your profile

Publications (238)1757.23 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Intermediate filament proteins form filaments, fibers and networks both in the cytoplasm and the nucleus of metazoan cells. Their general structural building plan accommodates highly varying amino acid sequences to yield extended dimeric α-helical coiled coils of highly conserved design. These 'rod' particles are the basic building blocks of intrinsically flexible, filamentous structures that are able to resist high mechanical stresses, that is, bending and stretching to a considerable degree, both in vitro and in the cell. Biophysical and computer modeling studies are beginning to unfold detailed structural and mechanical insights into these major supramolecular assemblies of cell architecture, not only in the 'test tube' but also in the cellular and tissue context. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Current Opinion in Cell Biology 02/2015; 32. DOI:10.1016/j.ceb.2015.01.001 · 8.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: More than 20 mutations in the gene encoding A-type lamins (LMNA) cause progeria, a rare premature aging disorder. The major pathognomonic hallmarks of progeria cells are seen as nuclear deformations or blebs that are related to the redistribution of A- and B-type lamins within the nuclear lamina. However, the functional significance of these progeria-associated blebs remains unknown. We have carried out an analysis of the structural and functional consequences of progeria-associated nuclear blebs in dermal fibroblasts from a progeria patient carrying a rare point mutation p.S143F (C428T) in lamin A/C. These blebs form microdomains that are devoid of major structural components of the nuclear envelope (NE)/lamina including B-type lamins and nuclear pore complexes (NPCs) and are enriched in A-type lamins. Using laser capture microdissection and comparative genomic hybridization (CGH) analyses, we show that, while these domains are devoid of centromeric heterochromatin and gene-poor regions of chromosomes, they are enriched in gene-rich chromosomal regions. The active form of RNA polymerase II is also greatly enriched in blebs as well as nascent RNA but the nuclear co-activator SKIP is significantly reduced in blebs compared to other transcription factors. Our results suggest that the p.S143F progeria mutation has a severe impact not only on the structure of the lamina but also on the organization of interphase chromatin domains and transcription. These structural defects are likely to contribute to gene expression changes reported in progeria and other types of laminopathies.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nuclear lamins play important roles in the organization and structure of the nucleus; however, the specific mechanisms linking lamin structure to nuclear functions are poorly defined. We demonstrate that reducing nuclear lamin B1 expression by shRNA-mediated silencing in cancer cell lines to approximately 50% of normal levels causes a delay of the cell cycle and an accumulation of cells in early S phase. The S phase delay appears to be due to the stalling and collapse of replication forks. The double strand DNA breaks resulting from replication fork collapse were inefficiently repaired causing persistent DNA damage signaling and the assembly of extensive repair foci on chromatin. The expression of multiple factors involved in DNA replication and DNA repair by both non-homologous end joining and homologous repair is misregulated when lamin B1 levels are reduced. We further demonstrate that lamin B1 interacts directly with the promoters of some genes associated with DNA damage response and repair including BRCA1 and RAD51. Taken together the results suggest that the maintenance of lamin B1 levels is required for DNA replication and repair through regulating the expression of key factors involved in these essential nuclear functions. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
    Molecular and Cellular Biology 12/2014; 35(5). DOI:10.1128/MCB.01145-14 · 5.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study demonstrates that the association of mitochondria with vimentin intermediate filaments (VIFs) measurably increases their membrane potential. This increase is detected by quantitatively comparing the fluorescence intensity of mitochondria stained with the membrane potential-sensitive dye tetramethylrhodamine-ethyl ester (TMRE) in murine vimentin-null fibroblasts with that in the same cells expressing human vimentin (∼35% rise). When vimentin expression is silenced by small hairpin RNA (shRNA) to reduce vimentin by 90%, the fluorescence intensity of mitochondria decreases by 20%. The increase in membrane potential is caused by specific interactions between a subdomain of the non-α-helical N terminus (residues 40 to 93) of vimentin and mitochondria. In rho 0 cells lacking mitochondrial DNA (mtDNA) and consequently missing several key proteins in the mitochondrial respiratory chain (ρ(0) cells), the membrane potential generated by an alternative anaerobic process is insensitive to the interactions between mitochondria and VIF. The results of our studies show that the close association between mitochondria and VIF is important both for determining their position in cells and their physiologic activity.-Chernoivanenko, I. S., Matveeva, E. A., Gelfand, V. I., Goldman, R. D., and Minin, A. A. Mitochondrial membrane potential is regulated by vimentin intermediate filaments. © FASEB.
    The FASEB Journal 11/2014; DOI:10.1096/fj.14-259903 · 5.48 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Telomeres protect the ends of linear genomes, and the gradual loss of telomeres is associated with cellular ageing. Telomere protection involves the insertion of the 3' overhang facilitated by telomere repeat-binding factor 2 (TRF2) into telomeric DNA, forming t-loops. We present evidence suggesting that t-loops can also form at interstitial telomeric sequences in a TRF2-dependent manner, forming an interstitial t-loop (ITL). We demonstrate that TRF2 association with interstitial telomeric sequences is stabilized by co-localization with A-type lamins (lamin A/C). We also find that lamin A/C interacts with TRF2 and that reduction in levels of lamin A/C or mutations in LMNA that cause an autosomal dominant premature ageing disorder-Hutchinson Gilford Progeria Syndrome (HGPS)-lead to reduced ITL formation and telomere loss. We propose that cellular and organismal ageing are intertwined through the effects of the interaction between TRF2 and lamin A/C on chromosome structure.
    Nature Communications 11/2014; 5:5467. DOI:10.1038/ncomms6467 · 10.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Molecular motors in cells typically produce highly directed motion; however, the aggregate, incoherent effect of all active processes also creates randomly fluctuating forces, which drive diffusive-like, nonthermal motion. Here, we introduce force-spectrum-microscopy (FSM) to directly quantify random forces within the cytoplasm of cells and thereby probe stochastic motor activity. This technique combines measurements of the random motion of probe particles with independent micromechanical measurements of the cytoplasm to quantify the spectrum of force fluctuations. Using FSM, we show that force fluctuations substantially enhance intracellular movement of small and large components. The fluctuations are three times larger in malignant cells than in their benign counterparts. We further demonstrate that vimentin acts globally to anchor organelles against randomly fluctuating forces in the cytoplasm, with no effect on their magnitude. Thus, FSM has broad applications for understanding the cytoplasm and its intracellular processes in relation to cell physiology in healthy and diseased states.
    Cell 08/2014; 158(4):822-32. DOI:10.1016/j.cell.2014.06.051 · 33.12 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The semiflexible polymers filamentous actin (F-actin) and intermediate filaments (IF) both form complex networks within the cell, and together are key determinants of cellular stiffness. While the mechanics of F-actin networks together with stiff microtubules have been characterized, the interplay between F-actin and IF networks is largely unknown, necessitating the study of composite networks using mixtures of semiflexible biopolymers. We employ bulk rheology in a simplified in vitro system to uncover the fundamental mechanical interactions between networks of the 2 semiflexible polymers, F-actin and vimentin IF. Surprisingly, co-polymerization of actin and vimentin can produce composite networks either stronger or weaker than pure F-actin networks. We show that this effect occurs through steric constraints imposed by IF on F-actin during network formation and filament crosslinking, highlighting novel emergent behavior in composite semiflexible networks.
    05/2014; 4(4-5):138-43. DOI:10.4161/19490992.2014.989035
  • [Show abstract] [Hide abstract]
    ABSTRACT: Nuclear lamins form the major structural elements comprising the nuclear lamina. While loss of nuclear structural integrity has been implicated as a key factor in the lamin A gene mutations causing laminopathies, the normal regulation of lamin A/C (LA/C) assembly and organization in interphase cells is still undefined. We assumed phosphorylation to be a major determinant, identifying 21 prime interphase phosphorylation sites, with 8 high turnover sites. The roles of these latter sites were examined by site-directed mutagenesis, followed by detailed microscopic analysis, including fluorescence recovery after photobleaching, fluorescence correlation spectroscopy, and nuclear extraction techniques. Results reveal three phosphorylation regions, each with dominant sites, together controlling LA/C structure and dynamics. Interestingly, two of these interphase sites are hyperphosphorylated in mitotic cells and one is within the sequence missing in progerin of the Hutchinson Gilford Progeria Syndrome. A model is presented where different phosphorylation combinations will yield markedly different effects on the assembly, subunit turnover, and mobility of LA/C between and within the lamina, the nucleoplasm, and the cytoplasm of interphase cells.
    Journal of Cell Science 04/2014; 127(12):2683-2696. DOI:10.1242/jcs.141820 · 5.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The nuclear lamina (NL) consists of lamin polymers and proteins that bind to the polymers. Disruption of NL proteins such as lamin and emerin leads to developmental defects and human diseases. However, the expression of multiple lamins, including lamin-A/C, lamin-B1, and lamin-B2, in mammals has made it difficult to study the assembly and function of the NL. Consequently, it remains unclear whether different lamins depend on one another for proper NL assembly and which NL functions are shared by all lamins or are specific to one lamin. Using mouse cells deleted of all or different combinations of lamins, we demonstrate that the assembly of each lamin into NL depends primarily on the lamin concentration present in the nucleus. When expressed at sufficiently high levels, each lamin alone can assemble into an evenly organized NL, which is in turn sufficient to ensure the even distribution of the nuclear pore complexes (NPC). By contrast, only lamin-A can ensure the localization of emerin within the NL. Thus, when investigating the role of the NL in development and disease, it is critical to determine the protein levels of relevant lamins and the intricate shared or specific lamin functions in the tissue of interest.
    Molecular biology of the cell 02/2014; DOI:10.1091/mbc.E13-11-0644 · 5.98 Impact Factor
  • Takeshi Shimi, Robert D Goldman
    [Show abstract] [Hide abstract]
    ABSTRACT: In mammalian cells, the nuclear lamina is composed of a complex fibrillar network associated with the inner membrane of the nuclear envelope. The lamina provides mechanical support for the nucleus and functions as the major determinant of its size and shape. At its innermost aspect it associates with peripheral components of chromatin and thereby contributes to the organization of interphase chromosomes. The A- and B-type lamins are the major structural components of the lamina, and numerous mutations in the A-type lamin gene have been shown to cause many types of human diseases collectively known as the laminopathies. These mutations have also been shown to cause a disruption in the normal interactions between the A and B lamin networks. The impact of these mutations on nuclear functions is related to the roles of lamins in regulating various essential processes including DNA synthesis and damage repair, transcription and the regulation of genes involved in the response to oxidative stress. The major cause of oxidative stress is the production of reactive oxygen species (ROS), which is critically important for cell proliferation and longevity. Moderate increases in ROS act to initiate signaling pathways involved in cell proliferation and differentiation, whereas excessive increases in ROS cause oxidative stress, which in turn induces cell death and/or senescence. In this review, we cover current findings about the role of lamins in regulating cell proliferation and longevity through oxidative stress responses and ROS signaling pathways. We also speculate on the involvement of lamins in tumor cell proliferation through the control of ROS metabolism.
    Advances in Experimental Medicine and Biology 01/2014; 773:415-30. DOI:10.1007/978-1-4899-8032-8_19 · 2.01 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Significant efforts have addressed the role of vimentin intermediate filaments (VIF) in cell motility, shape, adhesion and their connections to microfilaments (MF) and microtubules (MT). The present work uses micropatterned substrates to control the shapes of mouse fibroblasts and demonstrates that the cytoskeletal elements are dependent on each other and that unlike MF, VIF are globally controlled. For example, both square and circle shaped cells have a similar VIF distribution while MF distributions in these two shapes are quite different and depend on the curvature of the shape. Furthermore, in asymmetric and polarized shaped cells VIF avoid the sharp edges where MF are highly localized. Experiments with vimentin null mouse embryonic fibroblasts (MEFs) adherent to polarized (teardrop) and un-polarized (dumbbell) patterns show that the absence of VIF alters microtubule organization and perturbs cell polarity. The results of this study also demonstrate the utility of patterned substrates for quantitative studies of cytoskeleton organization in adherent cells.
    Biomaterials 11/2013; DOI:10.1016/j.biomaterials.2013.10.008 · 8.31 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The mechanical properties of a cell determine many aspects of its behavior, and these mechanics are largely determined by the cytoskeleton. Although the contribution of actin filaments and microtubules to the mechanics of cells has been investigated in great detail, relatively little is known about the contribution of the third major cytoskeletal component, intermediate filaments (IFs). To determine the role of vimentin IF (VIF) in modulating intracellular and cortical mechanics, we carried out studies using mouse embryonic fibroblasts (mEFs) derived from wild-type or vimentin(-/-) mice. The VIFs contribute little to cortical stiffness but are critical for regulating intracellular mechanics. Active microrheology measurements using optical tweezers in living cells reveal that the presence of VIFs doubles the value of the cytoplasmic shear modulus to ∼10 Pa. The higher levels of cytoplasmic stiffness appear to stabilize organelles in the cell, as measured by tracking endogenous vesicle movement. These studies show that VIFs both increase the mechanical integrity of cells and localize intracellular components.
    Biophysical Journal 10/2013; 105(7):1562-1568. DOI:10.1016/j.bpj.2013.08.037 · 3.83 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The nuclear lamins play important roles in the structural organization and function of the metazoan cell nucleus. Recent studies on B-type lamins identified a requirement for lamin B1 (LB1) in the regulation of cell proliferation in normal diploid cells. In order to further investigate the function of LB1 in proliferation, we disrupted its normal expression in U-2 OS human osteosarcoma and other tumor cell lines. Silencing LB1 expression induced G1 cell cycle arrest without significant apoptosis. The arrested cells are unable to mount a timely and effective response to DNA damage induced by UV irradiation. Several proteins involved in the detection and repair of UV damage by the nucleotide excision repair (NER) pathway are down-regulated in LB1 silenced cells including DDB1, CSB and PCNA. We propose that LB1 regulates the DNA damage response to UV irradiation by modulating the expression of specific genes and activating persistent DNA damage signaling. Our findings are relevant to understanding the relationship between the loss of LB1 expression, DNA damage signaling, and replicative senescence.
    PLoS ONE 07/2013; 8(7):e69169. DOI:10.1371/journal.pone.0069169 · 3.53 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Giant axonal neuropathy (GAN) is an early-onset neurological disorder caused by mutations in the GAN gene (encoding for gigaxonin), which is predicted to be an E3 ligase adaptor. In GAN, aggregates of intermediate filaments (IFs) represent the main pathological feature detected in neurons and other cell types, including patients' dermal fibroblasts. The molecular mechanism by which these mutations cause IFs to aggregate is unknown. Using fibroblasts from patients and normal individuals, as well as Gan-/- mice, we demonstrated that gigaxonin was responsible for the degradation of vimentin IFs. Gigaxonin was similarly involved in the degradation of peripherin and neurofilament IF proteins in neurons. Furthermore, proteasome inhibition by MG-132 reversed the clearance of IF proteins in cells overexpressing gigaxonin, demonstrating the involvement of the proteasomal degradation pathway. Together, these findings identify gigaxonin as a major factor in the degradation of cytoskeletal IFs and provide an explanation for IF aggregate accumulation, the subcellular hallmark of this devastating human disease.
    Journal of Clinical Investigation 04/2013; DOI:10.1172/JCI66387 · 13.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A two-component continuum elastic model is introduced to analyze a nuclear lamin meshwork, a structural element of the lamina of the nuclear envelope. The main component of the lamina is a meshwork of lamin protein filaments providing mechanical support to the nucleus and also playing a role in gene expression. Abnormalities in nuclear shape are associated with a variety of pathologies, including some forms of cancer and Hutchinson-Gilford progeria syndrome, and are often characterized by protruding structures termed nuclear blebs. Nuclear blebs are rich in A-type lamins and may be related to pathological gene expression. We apply the two-dimensional elastic shell model to determine which characteristics of the meshwork could be responsible for blebbing, including heterogeneities in the meshwork thickness and mesh size. We find that if one component of the lamin meshwork, rich in A-type lamins, has a tendency to form a larger mesh size than that rich in B-type lamins, this is sufficient to cause segregation of the lamin components and also to form blebs rich in A-type lamins. The model produces structures with comparable morphologies and mesh size distributions as the lamin meshworks of real, pathological nuclei.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Lamin A and the B-type lamins, lamin B1 and lamin B2, are translated as pre-proteins that are modified at a carboxyl terminal CAAX motif by farnesylation, proteolysis and carboxymethylation. Lamin A is further processed by proteolysis to remove the farnesyl, but B-type lamins remain permanently farnesylated. Two childhood diseases, Hutchinson Gilford Progeria Syndrome and restrictive dermopathy are caused by defects in the processing of lamin A, resulting in permanent farnesylation of the protein. Farnesyltransferase inhibitors, originally developed to target oncogenic Ras, have recently been used in clinical trials to treat children with Hutchinson Gilford Progeria Syndrome. Lamin B1 and lamin B2 play important roles in cell proliferation and organ development, but little is known about the role of farnesylation in their functions. Treating normal human fibroblasts with farnesyltransferase inhibitors causes the accumulation of unprocessed lamin B2 and lamin A and a decrease in mature lamin B1. Normally, lamins are concentrated at the nuclear envelope/lamina, but when farnesylation is inhibited, the peripheral localization of lamin B2 decreases as its nucleoplasmic levels increase. Unprocessed prelamin A distributes into both the nuclear envelope/lamina and nucleoplasm. Farnesyltransferase inhibitors also cause a rapid cell cycle arrest leading to cellular senescence. This study suggests that the long-term inhibition of protein farnesylation could have unforeseen consequences on nuclear functions.
    Nucleus (Austin, Texas) 03/2013; 4(2). · 3.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Much of the structural stability of the nucleus comes from meshworks of intermediate filament proteins known as lamins forming the inner layer of the nuclear envelope called the nuclear lamina. These lamin meshworks additionally play a role in gene expression. Abnormalities in nuclear shape are associated with a variety of pathologies, including some forms of cancer and Hutchinson-Gilford Progeria Syndrome, and often include protruding structures termed nuclear blebs. These nuclear blebs are thought to be related to pathological gene expression; however, little is known about how and why blebs form. We have developed a minimal continuum elastic model of a lamin meshwork that we use to investigate which aspects of the meshwork could be responsible for bleb formation. Mammalian lamin meshworks consist of two types of lamin proteins, A type and B type, and it has been reported that nuclear blebs are enriched in A-type lamins. Our model treats each lamin type separately and thus, can assign them different properties. Nuclear blebs have been reported to be located in regions where the fibers in the lamin meshwork have a greater separation, and we find that this greater separation of fibers is an essential characteristic for generating nuclear blebs. The model produces structures with comparable morphologies and distributions of lamin types as real pathological nuclei. Thus, preventing this opening of the meshwork could be a route to prevent bleb formation, which could be used as a potential therapy for the pathologies associated with nuclear blebs.
    Proceedings of the National Academy of Sciences 02/2013; 110(9):3248-53. DOI:10.1073/pnas.1300215110 · 9.81 Impact Factor
  • Source
    Puneet Opal, Robert D Goldman
    [Show abstract] [Hide abstract]
    ABSTRACT: Giant axonal neuropathy (GAN)(1) is a rare autosomal recessive neurological disorder caused by mutations in the GAN gene that encodes gigaxonin, a member of the BTB/Kelch family of E3 ligase adaptor proteins.(1) This disease is characterized by the aggregation of Intermediate Filaments (IF)-cytoskeletal elements that play important roles in cell physiology including the regulation of cell shape, motility, mechanics and intra-cellular signaling. Although a range of cell types are affected in GAN, neurons display the most severe pathology, with neuronal intermediate filament accumulation and aggregation; this in turn causes axonal swellings or "giant axons." A mechanistic understanding of GAN IF pathology has eluded researchers for many years. In a recent study(1) we demonstrate that the normal function of gigaxonin is to regulate the degradation of IF proteins via the proteasome. Our findings present the first direct link between GAN mutations and IF pathology; moreover, given the importance of IF aggregations in a wide range of disease conditions, our findings could have wider ramifications.
    01/2013; 1:e25378. DOI:10.4161/rdis.25378

Publication Stats

16k Citations
1,757.23 Total Impact Points


  • 2004–2014
    • Northwestern University
      • • Department of Cell and Molecular Biology
      • • Feinberg School of Medicine
      Evanston, Illinois, United States
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France
    • University of Turku
      • Department of Biology
      Turku, Western Finland, Finland
  • 2013
    • Harvard University
      • School of Engineering and Applied Sciences
      Cambridge, MA, United States
  • 2009
    • Åbo Akademi University
      • Department of Biology
      Turku, Western Finland, Finland
  • 1983–2008
    • University of Illinois at Chicago
      • Department of Anatomy and Cell Biology (Chicago)
      Chicago, Illinois, United States
  • 1996
    • State University of New York
      New York, New York, United States
  • 1993–1996
    • Johns Hopkins Medicine
      Baltimore, Maryland, United States
  • 1992
    • University of Rochester
      Rochester, New York, United States
  • 1989
    • University of Wisconsin–Madison
      • Laboratory of Cell and Molecular Biology
      Madison, Wisconsin, United States
  • 1985
    • Marine Biological Laboratory
      Falmouth, Massachusetts, United States
  • 1984
    • University of Colorado at Boulder
      Boulder, Colorado, United States
  • 1976–1981
    • Carnegie Mellon University
      • Department of Biological Sciences
      Pittsburgh, Pennsylvania, United States
    • Cold Spring Harbor Laboratory
      Cold Spring Harbor, New York, United States
  • 1970–1974
    • Case Western Reserve University
      • Department of Biology
      Cleveland, Ohio, United States
    • Institute of Human Virology
      Maryland City, Maryland, United States