Microsomal p450s use specific proline-rich sequences for efficient folding, but not for maintenance of the folded structure.

The amino-terminal region of microsomal P450s contains three distinct sequence motifs, the signal-anchor sequence (SA), the basic sequence (BS), and the proline-rich sequence (PR). Studies with two P450s of the CYP2C subfamily, P4502C11 (CYP2C11) and P4502C2 (CYP2C2), have indicated that upon expression in eukaryotic cells (yeast, COS cells, and insect cells), specific proline residues in PR are important for proper folding. In the present study, we have established that the PR region in a very different CYP gene family, P450c17 (CYP17), is also important for efficient folding.

Aluminium and cadmium inhibit vitellogenin and its mRNA induction by estradiol-17 beta in the primary culture of hepatocytes in the rainbow trout Oncorhynchus mykiss.

Effects of Al and Cd on vitellogenin (VTG) and VTG mRNA induction by estradiol-17 beta (E(2)) were examined in primary hepatocyte cultures of rainbow trout. Hepatocytes were precultured for 2 days and then E(2) (2 x 10(-6) M) and Al (10(-6)-10(-4) M) or Cd (10(-9)-10(-6) M) were simultaneously added to the incubation medium. Hepatocytes were cultured for 5 more days.

Three zinc finger nuclear proteins, Sp1, Sp3, and a ZBP-89 homologue, bind to the cyclic adenosine monophosphate-responsive sequence of the bovine adrenodoxin gene and regulate transcription.

Adrenocorticotropin acting through cyclic adenosine monophosphate (cAMP) regulates transcription of the bovine adrenodoxin (Adx) gene in the adrenal cortex. The bovine Adx cAMP-responsive transcription sequence (CRS) has previously been found to contain two consensus GC boxes. By use of nuclear extracts from adrenocortical cells, Sp1 and Sp3 are shown here to bind to CRS.

Protein synthesis inhibitors and ethanol selectively enhance heterologous expression of P450s and related proteins in Escherichia coli.

The antibiotics chloramphenicol (Cm), tetracycline, and erythromycin, which inhibit bacterial protein synthesis and are known to induce the cold shock response, unexpectedly enhance the heterologous expression of P450s and related proteins in Escherichia coli. In contrast, antibiotics that mimic heat shock in E. coli such as puromycin, streptomycin, and kanamycin decrease the expression of the same proteins.

The bovine CYP17 promoter contains a transcriptional regulatory element cooperatively bound by tale homeodomain proteins.

Bovine CYP17 is regulated at the transcriptional level by ACTH acting through the second messenger cAMP in adrenal fasciculata and reticularis cells. Promoter analysis has previously identified two regions, proximal and distal, within the CYP17 promoter important in the cAMP dependent transcriptional regulation of this gene. The proximal (-80 to -40) cAMP responsive sequence (CRS2) has been identified as a binding site for Steroidogenic Factor-1 (SF-1)/Ad4BP.

Structure/function relationship of CYP11B1 associated with Dahl's salt-resistant rats--expression of rat CYP11B1 and CYP11B2 in Escherichia coli.

Dahl's salt-resistant normotensive rats (DR rats) have been previously reported to express cytochrome P-450 (CYP11B1) containing five missense mutations [Matsukawa, N., Nonaka, Y., Higaki, J.

[The regulation of steroidogenesis by 17 alpha-hydroxylase/17,20-lyase (P450c17)].

Cytochrome P450c17 (P450c17) catalyzes 17 alpha-hydroxylation and 17, 20-lyase reactions. This enzyme plays a key role in determination of the balance between glucocorticoids and steroid sex hormones. In this review we discuss recent progress in the studies of both transcriptional regulation of CYP17 encoding P450c17 and enzymatic regulation of P450c17.

Members of the meis1 and pbx homeodomain protein families cooperatively bind a cAMP-responsive sequence (CRS1) from bovine CYP17.

The mammalian Pbx homeodomain proteins provide specificity and increased DNA binding affinity to other homeodomain proteins. A cAMP-responsive sequence (CRS1) from bovine CYP17 has previously been shown to be a binding site for Pbx1. A member of a second mammalian homeodomain family, Meis1, is now also demonstrated to be a CRS1-binding protein upon purification using CRS1 affinity chromatography.

Evidence that immature rat liver is capable of participating in steroidogenesis by expressing 17alpha-hydroxylase/17,20-lyase P450c17.

Steroid hydroxylase cytochrome P450c17 has been previously purified from microsomal fractions of immature rat livers. In this study, we investigated the expression of P450c17 in rat livers to understand a role of steroidogenesis in the extrasteroidogenic tissue. Upon immunoblot analysis utilizing liver microsomes from rats, P450c17 was detected in 1 and 3 week old rats but not in adult rats.

[A case of progressive right coronary ostial stenosis after Carrel patch method using gelatin-resorcin-formalin glue].

A 31-year-old man with type A chronic aortic dissection associated with annuloaortic ectasia underwent the concomitant graft replacement of the total aortic root and the transverse aortic arch. The two coronary arteries were reconstructed using the Carrel patch method. The false lumen of right coronary artery was closed by injection of GRF glue into the dissected space and compressing the dissected layers.

The homeodomain protein Pbx1 is involved in cAMP-dependent transcription of human CYP17.

Pbx1 is a homeodomain transcription factor involved in cAMP-dependent transcriptional regulation of the bovine CYP17 gene. In this study, we have investigated the involvement of Pbx1 in the transcriptional regulation of the human CYP17 gene. Although a sequence identical to previously determined Pbx-binding sites is not present in the promoter region of the human CYP17 gene, three putative Pbx-binding sites are identified by sequence similarity analysis.

Escherichia coli flavodoxin sepharose as an affinity resin for cytochromes P450 and use to identify a putative cytochrome P450c17/3beta-hydroxysteroid dehydrogenase interaction.

Flavodoxin Sepharose (Fld Sepharose), a reagent originally developed to demonstrate an interaction between native Escherichia coli Fld and cytochrome P450c17, has been synthesized, using highly expressed (7 micromol Fld/liter E. coli culture) recombinant E. coli Fld, for use as an affinity resin for microsomal cytochromes P450.

CD34 expression by inflammatory fibroid polyps of the stomach.

The phenotype of the proliferated spindled cells and the histogenesis of inflammatory fibroid polyp (IFP) have been a matter of debate. To clarify the immunohistochemical profile of the main cellular component, we reviewed histologically and studied immunohistochemically 11 cases (12 lesions) of IFP of the stomach. The lesions ranged in size from 0.

cAMP-dependent transactivation involving the homeodomain protein Pbx1.

Pbx1 is a DNA-binding homeodomain protein originally discovered in the t(1;19) chromosomal translocation associated with pediatric pre-B acute lymphoblastic leukemia. Previously we reported a cAMP-regulatory sequence (CRS1) in the promoter region of the bovine CYP17 gene encoding steroid 17alpha-hydroxylase cytochrome P450 (P450c17) to be the first endogenous Pbx1 binding site and that overexpression of Pbx1 in mouse adrenal Y1 tumor cells enhances cAMP-dependent transcription mediated by this element. Here we report further characterization of Pbx1 binding site in CRS1 and role of Pbx1 in cAMP-dependent, CRS1-mediated transcription.

Protein kinase A-dependent transactivation by the E2A-Pbx1 fusion protein.

The chimeric gene E2A-PBX1 is formed by the t(1;19) chromosomal translocation exclusively associated with pediatric pre-B cell acute lymphoblastic leukemia (pre-B ALL). The resultant fusion protein from this chimeric gene contains the DNA-binding homeodomain of Pbx1. The first and only functional Pbx1 binding site has been localized in bovine CYP17 to a sequence (CRS1) that participates in cAMP-dependent transcription of this gene encoding the steroid hydroxylase, 17 alpha-hydroxylase cytochrome P450.

Active-site topology of bovine cholesterol side-chain cleavage cytochrome P450 (P450scc) and evidence for interaction of tyrosine 94 with the side chain of cholesterol.

Combining site-directed mutagenesis with analysis of the active-site topology of bovine cholesterol side-chain cleavage cytochrome P450scc (P450scc), we have investigated the roles of tyrosine residues 93 and 94 on substrate binding. Four single mutants (Y93A, Y93S, Y94A, and Y94S) and one double mutant (Y93S/Y94S) were examined. The largest increase in Ks was observed for binding of cholesterol and 25-hydroxycholesterol to the Y94S mutant (approximately 5.

Restricted usage of T cell receptor V alpha-V beta genes in infiltrating cells in the hearts of patients with acute myocarditis and dilated cardiomyopathy.

Prolonged myocardial cell damage initiated by acute myocarditis is thought to be one of the most important etiology of dilated cardiomyopathy. To investigate the immunological mechanisms involved in the pathogenesis of dilated cardiomyopathy, we analyzed the phenotypes of infiltrating cells and examined the expression of perforin in infiltrating cells in the hearts of patients with dilated cardiomyopathy as well as acute myocarditis. We also examined the expression of HLA and intercellular adhesion molecule-1 (ICAM-1) in myocardial tissue of these patients.

The role of cytochrome b5 in the biosynthesis of androgens by human P450c17.

Human cytochrome b5 has a profound effect on the 17,20-lyase activities catalyzed by purified, human cytochrome P450c17. It enhances the conversion of 17 alpha-hydroxypregnenolone to dehydroepiandrosterone by 13-fold and the conversion of 17 alpha-hydroxyprogesterone to androstenedione by at least 10-fold. This latter activity is virtually undetectable in the absence of cytochrome b5.

[Two cases of peripartum cardiomyopathy].

Two cases of peripartum cardiomyopathy, a rare type of dilated cardiomyopathy, are reported. A 36-year-old woman developed congestive heart failure 1 month after delivering her third child. Cardiac catheterization revealed diffuse hypokinesis of the left ventricle and an ejection fraction of 28%.

A cAMP-regulatory sequence (CRS1) of CYP17 is a cellular target for the homeodomain protein Pbx1.

Cytochrome P450c17 encoded by CYP17, whose expression is regulated by peptide hormones via cAMP, is required for cortisol and sex hormone biosynthesis thereby playing a key role in biological processes including sexual differentiation. Utilizing the cAMP-regulatory sequence CRS1 of the bovine CYP17 gene as an affinity ligand, four CRS1-binding proteins have been purified from nuclear extracts of mouse adrenocortical Y1 cells and shown to enhance the in vitro transcription of a reporter gene promoted by CRS1. Microsequencing of these four proteins established two of them to be the homeodomain proteins Pbx1a and Pbx1b, originally discovered by their involvement in the t(1;19) chromosomal translocation in pre-B-cell acute lymphoblastic leukemias.

[The life spans, cause of death and pathological findings of Fukuyama type congenital muscular dystrophy--analysis of 24 autopsy cases].

The case cards for autopsied patients with Fukuyama type congenital muscular dystrophy (FCMD) which included clinical data and pathological findings were filled in 10 national hospitals and 2 other institutes in Japan. The cards of 24 patients who died between 1978 and 1991 were collected and analysed for this study. The ages at death ranged from 2 to 27 years with a mean of 14.

Expression and purification of functional human 17 alpha-hydroxylase/17,20-lyase (P450c17) in Escherichia coli. Use of this system for study of a novel form of combined 17 alpha-hydroxylase/17,20-lyase deficiency.

Enzymatically active human 17 alpha-hydroxylase cytochrome P450 (P450c17) has been expressed in and purified from Escherichia coli. The cDNA containing modifications within the amino-terminal eight codons which are favorable for expression in E. coli, as well as codons for 4 histidine residues at the carboxyl terminus, was placed in the pCWori+ expression vector.

Immunohistochemical analysis of myoblast proliferation and differentiation in experimental skeletal muscle regeneration.

We investigated the onset and duration of DNA synthesis and differentiation of muscle precursor cells in the early stage in muscle regeneration after bupivacaine induced muscle necrosis using monoclonal anti-PCA and anti-desmin antibodies. The first positive PCNA reaction indicating the commencement of proliferating cycle of muscle precursor cells appeared at 24 hours after injury, and were most prominent at 60-72 hours after injury. Thereafter the reaction for PCNA disappeared as the maturation of regenerated myofibers progressed.

cAMP-dependent and tissue-specific expression of genes encoding steroidogenic enzymes in bovine luteal and granulosa cells in primary culture.

Steroidogenic enzymes are differentially expressed throughout the ovarian cycle. The complex pattern of cell-specific up- and down-regulation accounts, at least in part, for the cyclic production of estrogens, androgens and progesterone. The gonadotropins follicle-stimulating hormone and luteinizing hormone are the main regulators of ovarian steroid hormone production and act primarily via the cAMP second-messenger system.