Disease relevance of BZRP

• Bovine herpesvirus type 1 (BoHV-1) is the causative agent of respiratory and genital tract infections such as infectious rhinotracheitis (IBR), infectious pustular vulvovaginitis (IPV, balanoposthitis (IBP), and abortion [1].
• BHV1 subtypes 1 and 2a are mainly associated with the respiratory form of the disease (IBR), subtype 2b with IPV/IBP, and subtype 3 with encephalitis [2].

High impact information on BZRP

• The action of diazepam in adrenal mitochondria suggests that the mediation of corticotropin-induced steroidogenesis may be the physiological function of the peripheral-type benzodiazepine receptor [3].
• Cloning and expression of a pharmacologically unique bovine peripheral-type benzodiazepine receptor isoquinoline binding protein [4].
• Transfecting the cloned bovine PBR/IBP cDNA into COS-7 cells resulted in an 11-fold increase in the density of high affinity [3H]PK 11195 binding sites which had only low affinity for Ro5-4864 [4].
• Using a cDNA encoding a rat PBR/IBP to screen a fetal bovine adrenal cDNA library, a bovine cDNA encoding a polypeptide of 169 residues was cloned [4].
• The bovine and rat PBR/IBPs had similar hydropathy profiles exhibiting five potential transmembrane domains [4].

Anatomical context of BZRP

• Consistently, the major secretion of chromaffin cells, epinephrine dose-dependently stimulated StAR expression with no effect on PBR mRNA [5].
• The density of bovine peripheral-type benzodiazepine receptors (PBR) in four tissues was highest in adrenal cortex [6].
• The adrenal cortex PBR cofractionated with a mitochondrial membrane marker enzyme and could be solubilized with intact ligand binding properties using digitonin [6].
• We also examined the possible involvement of peripheral-type benzodiazepine receptor (PBR) in hemin/protoporphyrin IX-induced differentiation of K562 cells by the use of its ligands [7].
• Previous studies have indicated that peripheral benzodiazepine receptor (PBR) ligands inhibit aldosterone secretion in isolated adrenal zona glomerulosa cells although positive responses have been demonstrated in other steroidogenic tissues [8].

Associations of BZRP with chemical compounds

• High affinity binding of isoquinolines, such as PK 11195, is a conserved feature of peripheral-type benzodiazepine receptors (PBR) across species [4].
• The exchange of Met-154 for valine in the bovine PBR introduced a binding site for Ro5-4864, which is absent in the native PBR [9].
• By Northern analysis and the quantitative technique of TaqMan PCR we investigated whether chromaffin cells influence the regulation of StAR and the peripheral benzodiazepine receptor (PBR), both required for the rate-limiting step, the delivery of cholesterol to the inner mitochondrial membrane [5].
• Bovine pineal PBR were further characterized with compounds structurally related to either Ro 5-4864 or PK 11195.(ABSTRACT TRUNCATED AT 250 WORDS)[10]
• In conclusion, adrenomedullary secretory products are not necessary for the maintenance of PBR expression but facilitate steroid biosynthesis by increasing StAR mRNA expression and therefore can account for an ACTH-independent regulation of the rate-limiting step in steroidogenesis [5].

References