Disease relevance of Cabp1

• The functional role of CaBP in cellular Ca handling was investigated using a trophoblastic cell line, Rcho-1, derived from a rat choriocarcinoma [1].
• Conversely, a weaker tetanus stimulation allowed LTP induction and maintenance in CaBP-deficient mice [2].
• After a single 1,25(OH)(2) D injection (200 ng/100 g body weight), peak induction of TRPV6 mRNA was 2-fold greater (at 6 h) and CaBP mRNA was 20% higher in females (at 16 h) [3].
• An antiserum to a fourth Purkinje cell marker, vitamin D-dependent calcium-binding protein-28 kD (CaBP), reveals primarily axonless horizontal cells, but also subsets of rod bipolar, amacrine, and, in the mouse but not in the rabbit, ganglion cells [4].
• Computer imaging and immunohistochemical staining techniques were used to determine which midbrain dopaminergic (DA) cells are spared in Parkinson's disease (PD), and in animals treated with the DA neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and whether the spared cells contain the calcium-binding protein, calbindin-D28k (CaBP) [5].

Psychiatry related information on Cabp1

• Exactly what role PV plays in the claustrum is subject to discussion, but it can be postulated that, since CaBP is associated with GABAergic interneurons, synaptogenesis and neuronal maturation, it may also serve as a neuroprotectant, particularly with regard to pathologies associated with the aging process, such as in Alzheimer's disease [6].

High impact information on Cabp1

• This project aimed to determine the temporal and spatial expression of both CaBP proteins during early pregnancy and to establish whether they are necessary for blastocyst implantation [7].
• Calcium-binding protein, parvalbumin, is reduced in mutant mammalian muscle with abnormal contractile properties [8].
• In the brain, CaBP1 is found in the cerebral cortex and hippocampus, and in the retina this protein is found in cone bipolar and amacrine cells [9].
• Addition of 1,25-dihydroxycholecalciferol (calcitriol) to organ culture media with or without serum increased the amount and concentration of CaBP in yolk sac (p less than 0.001) at 48 h [10].
• On days 11-13 of gestation, the concentrations of immunoreactive CaBP in yolk sac were 4-5-fold higher than in placenta; by days 16-17, the concentrations in yolk sac and placenta were similar [10].

Biological context of Cabp1

• Slices of mouse or rat placental tissue (12-18-day gestation) were incubated with [3H]leucine and the biosynthesis of placental CaBP was quantified by an immunoprecipitation method using rabbit antiserum to rat intestinal CaBP [11].
• Under normal dietary conditions, the concentrations of CaBP in mouse placenta and intestine increased 6- and 3-fold, respectively, during the third trimester of pregnancy in parallel with the fetal demands for skeletal mineral [11].
• There were significant correlations of plasma 1,25(OH)2D to the intestinal absorption of 45Ca and 32P and to duodenal and renal CaBP [12].
• We report here the cloning of a full-length cDNA of the mouse CaBP which shows significant homology with calreticulin, an endoplasmic reticulum-associated Ca binding protein [1].
• To analyze the regulation of CaBP expression, placenta organ cultures and Rcho-1 cells were treated for 48 h in vitro with a series of agents implicated in Ca homeostasis [1].

Anatomical context of Cabp1

• A protein similar to rat intestinal calcium-binding protein (CaBP) has been identified in both mouse placenta and mouse small intestine [11].
• Yolk sac protein and purified rat intestinal CaBP displayed full identity upon immunodiffusion (Ouchterlony) using antiserum to the rat intestinal CaBP [10].
• In addition, the action of PTHrP on placental trophoblast Ca transport is likely to involve the regulation of CaBP expression to handle the increasing Ca requirements of the developing fetus [1].
• Upon differentiation, Rcho-1 cells exhibit enhanced Ca uptake compared to undifferentiated Rcho-1 stem cells, and CaBP expression is upregulated [1].
• The upregulation of CaBP expression during and/or following the differentiation of Rcho-1 cells into trophoblastic giant cells supports the importance of CaBP in trophoblast maturation and the validity of the Rcho-1 rat model cell system [1].

Associations of Cabp1 with chemical compounds

• Sodium dodecyl sulfate gel electrophoresis of the radioactive immune complex revealed a single 3H-labeled peak corresponding to the molecular weight of rat and mouse CaBP (10,050) [11].
• Immunoreactive CaBP in yolk sac homogenates eluted from gel permeation columns with the low molecular weight peak of 45Ca2+ binding (Chelex assay), and the electrophoretic mobility of the protein was markedly increased by EDTA [10].
• Thus, two immunologically distinct CaBPs, mol wt 10,000 and 28,000, are present in the adult mouse nephron; whereas, kidneys of adult rats, chickens, and saurian reptiles apparently contain significant levels of only 28,000 mol wt CaBP [13].
• Ca2+ binding to CaBP decreases its electrophoretic mobility in urea/polyacrylamide gels, changes its u.v. spectrum, increases the intrinsic tyrosine fluorescence intensity and strengthens hydrophobic interaction with the phenyl-Sepharose matrix [14].
• The fundamental biophysical properties of NMDA receptors and their number were not modified in CaBP-deficient mice [2].

Analytical, diagnostic and therapeutic context of Cabp1

• Further examination by an immunohistochemistry for calbindin-D 28k (CaBP) showed that a large number of immunoreactive Purkinje cells were atrophic and their dendritic trees were smaller and shorter than in wild-type littermates [15].
• Here we examined basal and vitamin D-regulated Ca absorption (in situ ligated loops) and mRNA levels for the apical membrane calcium channel, TRPV6, and the calcium binding protein, calbindin D(9k) (CaBP) mRNA levels (real-time PCR) in duodenum of female and male mice [3].
• Results were validated and confirmed by comparison to previous radioimmunoassay studies which indicated similar ratios of CaBP levels between brain regions/cell types.(ABSTRACT TRUNCATED AT 250 WORDS)[16]
• Northern blots revealed expression of the CaBP gene in cercariae but not in sporocyst or worm (developmental stages preceding and following cercaria) [17].
• In the present studies, electron microscopy was used to study the localization of CaBP in placenta [18].

References