scholarly journals Ca2+-binding protein of the human placenta. Characterization, immunohistochemical localization and functional involvement in Ca2+ transport

1985 ◽  
Vol 227 (1) ◽  
pp. 317-326 ◽  
Author(s):  
R S Tuan
Keyword(s):  
Human Placenta ◽  
Binding Protein ◽  
Biochemical Properties ◽  
Immunohistochemical Localization ◽  
Chorionic Villi ◽  
Trophoblastic Cells ◽  
Functional Involvement ◽  
Microsomal Membranes ◽  
Specific Rabbit

The Ca2+-binding protein (HCaBP) of the human placenta was studied with respect to its biochemical properties, tissue and cellular distribution, and possible involvement in placental Ca2+ transport. Optimal Ca2+ binding by the HCaBP occurs at pH 7-8 and in 100 mM-Na+ and 3 mM-Ca2+. The HCaBP possesses at least 10 Ca2+-binding sites with a Kd of 5 × 10(-6) M ([Ca2+]). Highly specific rabbit-derived anti-HCaBP antibodies were used for HCaBP immunoquantification and immunohistochemistry, which revealed that the HCaBP is localized in the chorionic villi and is primarily associated with the trophoblastic cells of the placenta. In addition, an ‘in vitro’ cell-free assay system for Ca2+ uptake was constructed with microsomal membranes isolated from term placental tissues. Ca2+ uptake by the placental microsomal fraction exhibited characteristics indicative of active Ca2+ transport such as temperature-dependence, saturability and energetic requirement. In this system, preincubation of microsomal membranes with anti-HCaBP antibodies inhibited Ca2+ uptake, suggesting that the HCaBP is functionally involved in placental membrane Ca2+ uptake.

scholarly journals Interactions among p22, glyceraldehyde-3-phosphate dehydrogenase and microtubules

2004 ◽  
Vol 384 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Josefa ANDRADE ◽  
Sandy Timm PEARCE ◽  
Hu ZHAO ◽  
Margarida BARROSO
Keyword(s):  
Binding Protein ◽  
Direct Interaction ◽  
Independent Manner ◽  
Microtubule Associated Proteins ◽  
Binding Partners ◽  
Ef Hand ◽  
Associated Proteins ◽  
Microsomal Membranes ◽  
Terminal Amino

Previously, we have shown that p22, an EF-hand Ca2+-binding protein, interacts indirectly with microtubules in an N-myristoylation-dependent and Ca2+-independent manner. In the present study, we report that N-myristoylated p22 interacts with several microtubule-associated proteins within the 30–100 kDa range using overlay blots of microtubule pellets containing cytosolic proteins. One of those p22-binding partners, a 35–40 kDa microtubule-binding protein, has been identified by MS as GAPDH (glyceraldehyde-3-phosphate dehydrogenase). Several lines of evidence suggest a functional relationship between GAPDH and p22. First, endogenous p22 interacts with GAPDH by immunoprecipitation. Secondly, p22 and GAPDH align along microtubule tracks in analogous punctate structures in BHK cells. Thirdly, GAPDH facilitates the p22-dependent interactions between microtubules and microsomal membranes, by increasing the ability of p22 to bind microtubules but not membranes. We have also shown a direct interaction between N-myristoylated p22 and GAPDH in vitro with a KD of ∼0.5 μM. The removal of either the N-myristoyl group or the last six C-terminal amino acids abolishes the binding of p22 to GAPDH and reduces the ability of p22 to associate with microtubules. In summary, we report that GAPDH is involved in the ability of p22 to facilitate microtubule–membrane interactions by affecting the p22–microtubule, but not the p22–membrane, association.

scholarly journals Corticotropin-releasing hormone-binding protein: biochemistry and function from fishes to mammals

2002 ◽  
Vol 175 (1) ◽  
pp. 89-97 ◽  
Author(s):  
AF Seasholtz ◽  
RA Valverde ◽  
RJ Denver
Keyword(s):  
Binding Protein ◽  
Biological Effects ◽  
Biochemical Properties ◽  
Corticotropin Releasing Hormone ◽  
Releasing Hormone ◽  
Functional Conservation ◽  
And Function ◽  
Crh Receptors

Corticotropin-releasing hormone (CRH) plays multiple roles in vertebrate species. In mammals, it is the major hypothalamic releasing factor for pituitary adrenocorticotropin secretion, and is a neurotransmitter or neuromodulator at other sites in the central nervous system. In non-mammalian vertebrates, CRH not only acts as a neurotransmitter and hypophysiotropin, it also acts as a potent thyrotropin-releasing factor, allowing CRH to regulate both the adrenal and thyroid axes, especially in development. The recent discovery of a family of CRH-like peptides suggests that multiple CRH-like ligands may play important roles in these functions. The biological effects of CRH and the other CRH-like ligands are mediated and modulated not only by CRH receptors, but also via a highly conserved CRH-binding protein (CRH-BP). The CRH-BP has been identified not only in mammals, but also in non-mammalian vertebrates including fishes, amphibians, and birds, suggesting that it is a phylogenetically ancient protein with extensive structural and functional conservation. In this review, we discuss the biochemical properties of the characterized CRH-BPs and the functional roles of the CRH-BP. While much of the in vitro and in vivo data to date support an 'inhibitory' role for the CRH-BP in which it binds CRH and other CRH-like ligands and prevents the activation of CRH receptors, the possibility that the CRH-BP may also exhibit diverse extra- and intracellular roles in a cell-specific fashion and at specific times in development is also discussed.

β-Endorphin in the porcine ovary: immunohistochemical localization and follicular secretion in vitro

1989 ◽  
Vol 120 (3_Suppl) ◽  
pp. S202-S203
Author(s):  
G. WESTHOF ◽  
J. BENSCH ◽  
W. L. BRAENDLE
Keyword(s):  
Immunohistochemical Localization

Vitamin D binding protein (DBP) is required for pro-invasion effects of vitamin D on placental trophoblastic cells

2019 ◽  
Author(s):  
Ankana Ganguly ◽  
Alexandra Shattock ◽  
Annsha Joseph ◽  
Janesh Gupta ◽  
Martin Hewison
Keyword(s):  
Vitamin D ◽  
Binding Protein ◽  
Vitamin D Binding Protein ◽  
Trophoblastic Cells
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