Some Contributions of Phosphatase and 3,3'-Diaminobenzidine Cytochemistry to Cell Biology

1977 ◽  
Vol 35 ◽  
pp. 420-423
Author(s):  
Alex B. Novikoff
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Structure And Function ◽  
Cell Organelles ◽  
Thiamine Pyrophosphatase ◽  
The Status ◽  
Dab Cytochemistry ◽  
And Function

This presentation will highlight cytochemical studies that have illuminated some aspects of structure and function of the endoplasmic reticulum (ER); these have been reviewed recently (1, 2). Phosphatase (Pase) cytochemistry has led to the formulation of new questions regarding secretory mechanisms in a number of endocrine and exocrine cells; it has also made the status of GERL as a distinct organelle considerably firmer. 3,31-diaminobenzidine (DAB) cytochemistry has revealed the presence of an organelle apparently ubiquitous in mammalian cells, the anucleoid peroxisomes(microperoxisomes). DAB cytochemistry has been utilized recently by Gonatas et al. (3) to demonstrate that internalized plasma membrane is transported to GERL.Our initial use of Pase cytochemistry to visualize cell organelles included nucleoside diphosphatase (NDPase), thiamine pyrophosphatase (TPPase), and acid Pase (AcPase). NDPase hydrolyzes the diphosphates of inosine, uridine, and guanosine but not cytidine or adenine diphosphates. Since the work of Yamasaku and Hayaishi (4) we have used TPPase and NDPase interchangeably.

Oxidative protein folding in the mammalian endoplasmic reticulum

2004 ◽  
Vol 32 (5) ◽  
pp. 655-658 ◽  
Author(s):  
C.E. Jessop ◽  
S. Chakravarthi ◽  
R.H. Watkins ◽  
N.J. Bulleid
Keyword(s):  
Endoplasmic Reticulum ◽  
Mammalian Cells ◽  
Redox State ◽  
Structure And Function ◽  
Reduced Form ◽  
Secretory Proteins ◽  
Oxidative Protein Folding ◽  
Disulphide Bonds ◽  
And Function ◽  
Substrate Proteins

Native disulphide bonds are essential for the structure and function of many membrane and secretory proteins. Disulphide bonds are formed, reduced and isomerized in the endoplasmic reticulum of mammalian cells by a family of oxidoreductases, which includes protein disulphide isomerase (PDI), ERp57, ERp72, P5 and PDIR. This review will discuss how these enzymes are maintained in either an oxidized redox state that allows them to form disulphide bonds in substrate proteins or a reduced form that allows them to perform isomerization and reduction reactions, how these opposing pathways may co-exist within the same compartment and why so many oxidoreductases exist when PDI alone can perform all three of these functions.

Formation of chlamydospores in Gilbertella persicaria

1981 ◽  
Vol 59 (5) ◽  
pp. 908-928 ◽  
Author(s):  
Martha J. Powell ◽  
Charles E. Bracker ◽  
David J. Sternshein
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Light And Electron Microscopy ◽  
Multivesicular Bodies ◽  
Marker Enzyme ◽  
Transparent Layer ◽  
Thiamine Pyrophosphatase ◽  
Gilbertella Persicaria

The cytological events involved in the transformation of vegetative hyphae of the zygomycete Gilbertella persicaria (Eddy) Hesseltine into chlamydospores were studied with light and electron microscopy. Thirty hours after sporangiospores were inoculated into YPG broth, swellings appeared along the aseptate hyphae. Later, septa, traversed by plasmodesmata, delimited each end of the hyphal swellings and compartmentalized these hyphal regions as they differentiated into chlamydospores. Nonswollen regions adjacent to chlamydospores remained as isthmuses. Two additional wall layers appeared within the vegetative wall of the developing chlamydospores. An alveolate, electron-dense wall formed first, and then an electron-transparent layer containing concentrically oriented fibers formed between this layer and the plasma membrane. Rather than a mere condensation of cytoplasm, development and maturation of the multinucleate chlamydospores involved extensive cytoplasmic changes such as an increase in reserve products, lipid and glycogen, an increase and then disappearance of vacuoles, and the breakdown of many mitochondria. Underlying the plasma membrane during chlamydospore wall formation were endoplasmic reticulum, multivesicular bodies, vesicles with fibrillar contents, vesicles with electron-transparent contents, and cisternal rings containing the Golgi apparatus marker enzyme, thiamine pyrophosphatase. Acid phosphatase activity was localized cytochemically in a cisterna which enclosed mitochondria and in vacuoles which contained membrane fragments. Tightly packed membrane whorls and single membrane bounded sacs with finely granular matrices surrounding vacuoles were unique during chlamydospore development. Microbodies were rare in the mature chlamydospore, but endoplasmic reticulum was closely associated with lipid globules. As chlamydospores developed, the cytoplasm in the isthmus became highly vacuolated, lipid globules were closely associated with vacuoles, mitochondria were broken down in vacuoles, unusual membrane configurations appeared, and eventually the membranes degenerated. Unlike chlamydospores, walls of the isthmus did not thicken, but irregularly shaped appositions containing numerous channels formed at intervals on the inside of these walls. The pattern of cytoplasmic transformations during chlamydospore development is similar to events leading to the formation of zygospores and sporangiospores.

scholarly journals Discovery of keratin function and role in genetic diseases: the year that 1991 was

2016 ◽  
Vol 27 (18) ◽  
pp. 2807-2810 ◽  
Author(s):  
Pierre A. Coulombe
Keyword(s):  
Intermediate Filaments ◽  
Cell Biology ◽  
Essential Role ◽  
Genetic Diseases ◽  
Structure And Function ◽  
Mechanical Support ◽  
25Th Anniversary ◽  
Keratin Filaments ◽  
And Function ◽  
Keratin Intermediate Filaments

In 1991, a set of transgenic mouse studies took the fields of cell biology and dermatology by storm in providing the first credible evidence that keratin intermediate filaments play a unique and essential role in the structural and mechanical support in keratinocytes of the epidermis. Moreover, these studies intimated that mutations altering the primary structure and function of keratin filaments underlie genetic diseases typified by cellular fragility. This Retrospective on how these studies came to be is offered as a means to highlight the 25th anniversary of these discoveries.

scholarly journals ISOLATION OF A GOLGI APPARATUS-RICH FRACTION FROM RAT LIVER

1970 ◽  
Vol 44 (3) ◽  
pp. 492-500 ◽  
Author(s):  
R. D. Cheetham ◽  
D. James Morré ◽  
Wayne N. Yunghans
Keyword(s):  
Endoplasmic Reticulum ◽  
Uric Acid ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Rat Liver ◽  
Succinic Dehydrogenase ◽  
Acid Oxidase ◽  
Enzyme Substrate ◽  
Thiamine Pyrophosphatase ◽  
Cell Fractions

Enzymatic activities associated with Golgi apparatus-, endoplasmic reticulum-, plasma membrane-, mitochondria-, and microbody-rich cell fractions isolated from rat liver were determined and used as a basis for estimating fraction purity. Succinic dehydrogenase and cytochrome oxidase (mitochondria) activities were low in the Golgi apparatus-rich fraction. On the basis of glucose-6-phosphatase (endoplasmic reticulum) and 5'-nucleotidase (plasma membrane) activities, the Golgi apparatus-rich fraction obtained directly from sucrose gradients was estimated to contain no more than 10% endoplasmic reticulum- and 11% plasma membrane-derived material. Total protein contribution of endoplasmic reticulum, mitochondria, plasma membrane, microbodies (uric acid oxidase), and lysosomes (acid phosphatase) to the Golgi apparatus-rich fraction was estimated to be no more than 20–30% and decreased to less than 10% with further washing. The results show that purified Golgi apparatus fractions isolated routinely may exceed 80% Golgi apparatus-derived material. Nucleoside di- and triphosphatase activities were enriched 2–3-fold in the Golgi apparatus fraction relative to the total homogenate, and of a total of more than 25 enzyme-substrate combinations reported, only thiamine pyrophosphatase showed a significantly greater enrichment.

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