Developmental alterations in expression and subcellular localization of antizyme and antizyme inhibitor and their functional importance in the murine mammary gland

Amino Acids ◽  
2009 ◽  
Vol 38 (2) ◽  
pp. 591-601 ◽  
Author(s):  
Y. Murakami ◽  
J. Suzuki ◽  
K. Samejima ◽  
T. Oka
2004 ◽  
Vol 24 (20) ◽  
pp. 9059-9069 ◽  
Author(s):  
Andrea Farina ◽  
Masakazu Hattori ◽  
Jun Qin ◽  
Yoshihiro Nakatani ◽  
Nagahiro Minato ◽  
...  

ABSTRACT Brd4 is a mammalian protein that contains a double bromodomain. It binds to chromatin and regulates cell cycle progression at multiple stages. By immunopurification and mass spectrometry, we identified a Rap GTPase-activating protein (GAP), signal-induced proliferation-associated protein 1 (SPA-1), as a factor that interacts with Brd4. SPA-1 localizes to the cytoplasm and to a lesser degree in the nucleus, while Brd4 resides in the nucleus. Bifluorescence complementation revealed that Brd4 and SPA-1 interact with each other in the nucleus of living cells. Supporting the functional importance of the interaction, Brd4 enhanced Rap GAP activity of SPA-1. Furthermore ectopic expression of SPA-1 and Brd4 redirected subcellular localization of the partner and disrupted normal cell cycle progression. These effects were, however, reversed by coexpression of the two proteins, indicating that a proper balance between Brd4 and SPA-1 in G2 is required for cell division. This work reveals a novel link between Brd4 and a GTPase-dependent mitogenic signaling pathway.


Gene ◽  
2020 ◽  
Vol 759 ◽  
pp. 144981
Author(s):  
Fangting Zhou ◽  
Xiaohong Teng ◽  
Pei Wang ◽  
Yongyun Zhang ◽  
Yongwang Miao

2009 ◽  
Vol 107 (4) ◽  
pp. 732-740 ◽  
Author(s):  
Andrés J. López-Contreras ◽  
Berta L. Sánchez-Laorden ◽  
Bruno Ramos-Molina ◽  
María E. de la Morena ◽  
Asunción Cremades ◽  
...  

Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.


Author(s):  
I.C. Murray

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.


Author(s):  
J. Russo ◽  
W. Isenberg ◽  
M. Ireland ◽  
I.H. Russo

The induction of rat mammary carcinoma by the chemical carcinogen DMBA is used as a model for the study of the human disease (1). We previously described the histochemical changes that occur in the mammary gland of DMBA treated animals before the earliest manifested histological change, the intraductal proliferation (IDP), was observed (2). In the present work, we demonstrate that a change in the stable cell population found in the resting mammary gland occurs after carcinogen administration.Fifty-five day old Sprague-Dawley virgin female rats were inoculated intragastrically with 20mg of 7,12-dimethylbenz(a)anthracene (DMBA) in 1ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from control and inoculated rats were removed weekly from the time of inoculation until 60 days post-inoculation. For electron microscopy, the glands were immersed in Karnovsky's fixative, post-fixed in 1% OsO4, dehydrated, and embedded in an Epon-Araldite mixture. Thick (lμ) sections were stained with 1% toluidine blue and were used for selecting areas for ultrastructural study.


Author(s):  
J.M. Robinson ◽  
J.M Oliver

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.


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