scholarly journals The activity and subcellular distribution of the peroxisomal enzyme acyl-CoA oxidase in human blood platelets

1992 ◽  
Vol 286 (3) ◽  
pp. 829-831 ◽  
Author(s):  
M Farstad ◽  
A M Bakken ◽  
R K Berge
Keyword(s):  
Endoplasmic Reticulum ◽  
Human Blood ◽  
Subcellular Distribution ◽  
Blood Platelets ◽  
Peroxisomal Enzyme ◽  
Good Accordance ◽  
Tubular System ◽  
Acyl Coa Oxidase ◽  
Human Blood Platelets

The peroxisomal enzyme acyl-CoA oxidase is localized in the ‘dense-tubular-system-enriched fraction’, probably identical with the endoplasmic reticulum, in human blood platelets. This localization is strongly different from the localization of catalase which seems to be a cytosolic enzyme, in agreement with Marcus, Zucker-Franklin, Safir & Ullman [(1966) J. Clin. Invest. 45, 14-28]. A localization of acyl-CoA oxidase in the endoplasmic reticulum seems to be in good accordance with the important role of peroxisomes in the metabolism of prostaglandins, as recently demonstrated by Diczfalusy, Kase, Alexson & Bjørkhem [(1991) J. Clin. Invest. 88, 978-984].

Cytoskeletal ultrastructure and motility of cells

1980 ◽  
Vol 58 (7) ◽  
pp. 745-749 ◽  
Author(s):  
Robert Day Allen
Keyword(s):  
Human Blood ◽  
Blood Platelets ◽  
Contractile Proteins ◽  
Detailed Account ◽  
Dynamic Changes ◽  
Motile Cells ◽  
Human Blood Platelets

A brief review of the role of contractile proteins in dynamic changes in the cytoskeletons of motile cells is followed by a more detailed account of cytoskeletal ultrastructure in the motility of the giant amoeba, Chaos carolinensis and of human blood platelets.

Subcellular distribution of fibrinogen and factor XIII in human blood platelets

1976 ◽  
Vol 8 (4) ◽  
pp. 453-465 ◽  
Author(s):  
S Lopaciuk ◽  
K.M Lovette ◽  
Jan McDonagh ◽  
H.Y.K Chuang ◽  
R.P McDonagh
Keyword(s):  
Human Blood ◽  
Subcellular Distribution ◽  
Factor Xiii ◽  
Blood Platelets ◽  
Human Blood Platelets

VINCULIN ISOFORMS IN HUMAN BLOOD PLATELETS

1987 ◽  
Author(s):  
G M Asijee ◽  
T Bruin ◽  
A Sturk ◽  
J E ten Cate ◽  
L Muszbek
Keyword(s):  
Human Blood ◽  
Subcellular Distribution ◽  
Actin Filaments ◽  
Blood Platelets ◽  
Blood Platelet ◽  
Membrane Skeleton ◽  
Human Blood Platelet ◽  
Sds Page ◽  
Triton X ◽  
Human Blood Platelets

In several cells vinculin has been implicated in the interaction between the cytoskeleton and the outer ceil membrane. We have recently demonstrated that vinculin becomes associated with the Triton X-100 insoluble cytoskeleton of blood platelets upon thrombin-induced activation (Asijee et al, Exp Cell Res, 1987, in press). In the present study we demonstrate by SDS-PAGE and immunoblotting that vinculin is also present in the membrane skeleton of both non-activated and activated human blood platelets. The membrane skeleton was prepared by the method of Fox (J Clin Invest, 1985: 76, 1673), and platelets were stimulated 5 min at 37 °c with 0.1 U/ml thrombin. The association was specifically inhibited by DNase I-induced depolymerization of the actin filaments.Protein analysis by the O’Farrell technique (first dimension IEF, second dimension SDS-PAGE) and subsequent immunoblotting demonstrated purified vinculin to consist of 4 major isoforms (pI 6.8 - 7.2). These isoforms differed in subcellular distribution. Upon thrombin-induced platelet activation, cytoskeletal vinculin consisted of the 2 most acidic isoforms, and cytoplasmic vinculin of 2 more basic isoforms. The membrane skeleton-associated vinculin contained all 4 isoforms.We conclude that: 1. vinculin is a component of the membrane skeleton of both non-activated and activated human blood platelets, 2. similar to chicken gizzard smooth muscle cells, human blood platelet vinculin consists of several isoforms with differing subcellular distribution.

scholarly journals Cytochemical localization of ouabain-sensitive (K+)-dependent p-nitrophenyl phosphatase (transport ATPase) in human blood platelets.

1980 ◽  
Vol 28 (11) ◽  
pp. 1183-1188 ◽  
Author(s):  
L S Cutler ◽  
M B Feinstein ◽  
C P Christian
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Human Blood ◽  
Human Platelet ◽  
Blood Platelets ◽  
Cytochemical Localization ◽  
Transport Atpase ◽  
Tubular System ◽  
Membrane Compartments ◽  
Human Blood Platelets

The ultrastructural cytochemical localization of a potassium-dependent oubain-sensitive nitrophenyl phosphatase (transport ATPase) activity in human blood platelets is described. This potassium-dependent nitrophenyl phosphatase activity was not affected by 5 mM levamisole, indicating that the reaction product identified was not due to nonspecific alkaline phosphatase activity. The K+-dependent nitrophenyl phosphatase was strictly localized to the platelet plasma membrane, while the open canalicular system and dense tubular system were devoid of reaction product. In contrast, (Ca2+,Mg2+)-activated ATPase activity was predominantly localized in the open canalicular system and dense tubular system with very little cytochemical activity expressed at the plasma membrane. These data demonstrate a relative segregation of these enzymes into unique membrane compartments of the human platelet. Such data may be useful with regard to identification of purified membrane fractions from platelets and may be significant with regard to the understanding of the function(s) of the different membrane compartments of the human platelet.

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