scholarly journals The enduring enigma of nuclear translation

2012 ◽  
Vol 197 (1) ◽  
pp. 7-9 ◽  
Author(s):  
David W. Reid ◽  
Christopher V. Nicchitta
Keyword(s):  
Experimental Evidence ◽  
Cell Biology ◽  
Physical Separation ◽  
Cell Biol ◽  
Nuclear Translation

Although the physical separation of transcription in the nucleus and translation in the cytoplasm has presided as a fundamental tenet of cell biology for decades, it has not done so without recurring challenges and contentious debate. In this issue, David et al. (2012. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201112145) rekindle the controversy by providing convincing experimental evidence for nuclear translation.

scholarly journals A novel assay reveals preferential binding between Rabs, kinesins, and specific endosomal subpopulations

2015 ◽  
Vol 208 (3) ◽  
pp. 273-281 ◽  
Author(s):  
Marvin Bentley ◽  
Helena Decker ◽  
Julie Luisi ◽  
Gary Banker
Keyword(s):  
Experimental Evidence ◽  
Convenient Method ◽  
Cell Biology ◽  
Fundamental Problem ◽  
Family Members ◽  
Binding Domain ◽  
Late Endosomes ◽  
Early Endosomes ◽  
Preferential Binding ◽  
Candidate Protein

Identifying the proteins that regulate vesicle trafficking is a fundamental problem in cell biology. In this paper, we introduce a new assay that involves the expression of an FKBP12-rapamycin–binding domain–tagged candidate vesicle-binding protein, which can be inducibly linked to dynein or kinesin. Vesicles can be labeled by any convenient method. If the candidate protein binds the labeled vesicles, addition of the linker drug results in a predictable, highly distinctive change in vesicle localization. This assay generates robust and easily interpretable results that provide direct experimental evidence of binding between a candidate protein and the vesicle population of interest. We used this approach to compare the binding of Kinesin-3 family members with different endosomal populations. We found that KIF13A and KIF13B bind preferentially to early endosomes and that KIF1A and KIF1Bβ bind preferentially to late endosomes and lysosomes. This assay may have broad utility for identifying the trafficking proteins that bind to different vesicle populations.

scholarly journals Lipoprotein secretion: It takes two to TANGO

2016 ◽  
Vol 213 (3) ◽  
pp. 297-299 ◽  
Author(s):  
Suzanne R. Pfeffer
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Biology ◽  
Low Density Lipoproteins ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Cell Biol ◽  
Lipoprotein Secretion

An unsolved mystery in cell biology is how unusually large secretory cargoes are exported from the endoplasmic reticulum. In this issue, Santos et al. (2016. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201603072) report the function of a Mia2/cTAGE5 transcript fusion, named TALI, in the endoplasmic reticulum export of chylomicrons and very low-density lipoproteins, but not collagen XII.

How do memory modules differentially contribute to familiarity and recollection?

2019 ◽  
Vol 42 ◽  
Author(s):  
Olya Hakobyan ◽  
Sen Cheng
Keyword(s):  
Recognition Memory ◽  
Experimental Evidence ◽  
Subjective Experience ◽  
Target Article ◽  
Memory Modules ◽  
Familiarity And Recollection ◽  
Memory Contents

Abstract We fully support dissociating the subjective experience from the memory contents in recognition memory, as Bastin et al. posit in the target article. However, having two generic memory modules with qualitatively different functions is not mandatory and is in fact inconsistent with experimental evidence. We propose that quantitative differences in the properties of the memory modules can account for the apparent dissociation of recollection and familiarity along anatomical lines.

Redox Reactions in Lipid Membranes as a Model for Primordial Energy-Conserving Systems

1997 ◽  
Vol 161 ◽  
pp. 437-442
Author(s):  
Salvatore Di Bernardo ◽  
Romana Fato ◽  
Giorgio Lenaz
Keyword(s):  
Experimental Evidence ◽  
Lipid Membranes ◽  
Energy Supply ◽  
Redox Reactions ◽  
Living Systems ◽  
Asymmetric Distribution ◽  
Conservation Of Energy ◽  
Asymmetrical Distribution ◽  
Energy Conserving ◽  
Living Organisms

AbstractOne of the peculiar aspects of living systems is the production and conservation of energy. This aspect is provided by specialized organelles, such as the mitochondria and chloroplasts, in developed living organisms. In primordial systems lacking specialized enzymatic complexes the energy supply was probably bound to the generation and maintenance of an asymmetric distribution of charged molecules in compartmentalized systems. On the basis of experimental evidence, we suggest that lipophilic quinones were involved in the generation of this asymmetrical distribution of charges through vectorial redox reactions across lipid membranes.

Ultrastructure of Some Planktonic Formainifera

1974 ◽  
Vol 32 ◽  
pp. 190-191
Author(s):  
William H. Zucker
Keyword(s):  
Cell Biology ◽  
Water Mass ◽  
Planktonic Foraminifera ◽  
Uranyl Acetate ◽  
Ethanol Dehydration ◽  
Globigerinoides Ruber ◽  
Light Microscope Level ◽  
Globigerina Bulloides ◽  
Glutaraldehyde Solution ◽  
Diamond Knife

Planktonic foraminifera are widely-distributed and abundant zooplankters. They are significant as water mass indicators and provide evidence of paleotemperatures and events which occurred during Pleistocene glaciation. In spite of their ecological and paleological significance, little is known of their cell biology. There are few cytological studies of these organisms at the light microscope level and some recent reports of their ultrastructure.Specimens of Globigerinoides ruber, Globigerina bulloides, Globigerinoides conglobatus and Globigerinita glutinata were collected in Bermuda waters and fixed in a cold cacodylate-buffered 6% glutaraldehyde solution for two hours. They were then rinsed, post-fixed in Palade's fluid, rinsed again and stained with uranyl acetate. This was followed by graded ethanol dehydration, during which they were identified and picked clean of debris. The specimens were finally embedded in Epon 812 by placing each organism in a separate BEEM capsule. After sectioning with a diamond knife, stained sections were viewed in a Philips 200 electron microscope.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

1967 ◽  
Vol 25 ◽  
pp. 74-75
Author(s):  
L. V. Leak
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Green Algae ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Electron Microscopic ◽  
Photosynthetic Membranes ◽  
Blue Green Algae ◽  
Cell Biol ◽  
Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

Application of FRAP and digitized fluorescence microscopy to problems in cell membrane dynamics

1988 ◽  
Vol 46 ◽  
pp. 118-119
Author(s):  
K. Jacobson ◽  
A. Ishihara ◽  
B. Holifield ◽  
F. Zhang
Keyword(s):  
Fluorescence Microscopy ◽  
Cell Biology ◽  
Extended Period ◽  
Dynamic Structure ◽  
Living Cells ◽  
Membrane Dynamics ◽  
Molecular Cell Biology ◽  
Image Averaging ◽  
Single Living Cells ◽  
Single Living

Our laboratory is concerned with understanding the dynamic structure of the plasma membrane with particular reference to the movement of membrane constituents during cell locomotion. In addition to the standard tools of molecular cell biology, we employ both fluorescence recovery after photo- bleaching (FRAP) and digitized fluorescence microscopy (DFM) to investigate individual cells. FRAP allows the measurement of translational mobility of membrane and cytoplasmic molecules in small regions of single, living cells. DFM is really a new form of light microscopy in that the distribution of individual classes of ions, molecules, and macromolecules can be followed in single, living cells. By employing fluorescent antibodies to defined antigens or fluorescent analogs of cellular constituents as well as ultrasensitive, electronic image detectors and video image averaging to improve signal to noise, fluorescent images of living cells can be acquired over an extended period without significant fading and loss of cell viability.

A Method for Setting the Clearance Angle

1972 ◽  
Vol 30 ◽  
pp. 388-389
Author(s):  
Michael T. Bucek ◽  
Howard J. Arnott
Keyword(s):  
Experimental Evidence ◽  
Light Source ◽  
Black Spot ◽  
Critical Factor ◽  
Clearance Angle ◽  
Crude Approximation ◽  
Ultrathin Sections

It is believed by the authors, with supporting experimental evidence, that as little as 0.5°, or less, knife clearance angle may be a critical factor in obtaining optimum quality ultrathin sections. The degree increments located on the knife holder provides the investigator with only a crude approximation of the angle at which the holder is set. With the increments displayed on the holder one cannot set the clearance angle precisely and reproducibly. The ability to routinely set this angle precisely and without difficulty would obviously be of great assistance to the operator. A device has been contrived to aid the investigator in precisely setting the clearance angle. This device is relatively simple and is easily constructed. It consists of a light source and an optically flat, front surfaced mirror with a minute black spot in the center. The mirror is affixed to the knife by placing it permanently on top of the knife holder.

Correlative microscopy in distrubuted (client/server) computing environments: tools for catalyzing the rapid dissemination of information about the cell biology of the human prostate

1995 ◽  
Vol 53 ◽  
pp. 682-683
Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  
Keyword(s):  
United States ◽  
Cell Biology ◽  
Tissue Bank ◽  
The United States ◽  
Prostate Adenocarcinoma ◽  
Correlative Microscopy ◽  
Client Server ◽  
Critical Elements ◽  
Transplant Organ

Prostate adenocarcinoma is the most common malignant tumor of men in the United States and is the third leading cause of death in men. Despite attempts at early detection, there will be 244,000 new cases and 44,000 deaths from the disease in the United States in 1995. Therapeutic progress against this disease is hindered by an incomplete understanding of prostate epithelial cell biology, the availability of human tissues for in vitro experimentation, slow dissemination of information between prostate cancer research teams and the increasing pressure to “ stretch” research dollars at the same time staff reductions are occurring.To meet these challenges, we have used the correlative microscopy (CM) and client/server (C/S) computing to increase productivity while decreasing costs. Critical elements of our program are as follows:1) Establishing the Western Pennsylvania Genitourinary (GU) Tissue Bank which includes >100 prostates from patients with prostate adenocarcinoma as well as >20 normal prostates from transplant organ donors.

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