Cloning, structure, and expression of the mitochondrial cytochrome P-450 sterol 26-hydroxylase, a bile acid biosynthetic enzyme

Andersson, Stefan; Davis, Dana; Dahlbäck, Helena; Jörnvall, Hans; Russell, David W.

doi:10.1016/s0021-9258(18)83172-6

Cited by 1,184 publications

(97 citation statements)

References 44 publications

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“…This pattern, however, did not show a consis- tent variation with age but appeared more to reflect differences between individuals. A pattern of more than one CYP27A1 mRNA transcript has previously been reported in tissues from pig, rat, and rabbit (32,37,38).…”

Section: Hepatic Mitochondrial Cyp27a1mentioning

confidence: 64%

Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences

Norlin

2002

Journal of Lipid Research

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The developmental variation of cytochrome P450 (CYP)7A1, CYP7B1, CYP27A1, and 3 ␤ -hydroxy-⌬ 5 -C 27 -steroid dehydrogenase, key enzymes in bile acid biosynthesis, were investigated in pigs of different ages. As part of these studies, peptide sequences from a purified pig liver oxysterol 7 ␣ -hydroxylase were analyzed. The sequences showed a high degree of identity with those of murine and human CYP7B1. Enzymatic activities and mRNA levels of CYP27A1 and 3 ␤ -hydroxy-⌬ 5 -C 27 -steroid dehydrogenase were similar in livers of newborn and 6-month-old pigs. Enzymatic activity mediated by CYP7A1 increased several-fold between infancy and adolescence. Hepatic CYP7A1 and CYP7B1 mRNA levels increased several-fold with age. Hepatic microsomal 7 ␣ -hydroxylation of 27-hydroxycholesterol and dehydroepiandrosterone, substrates typical for CYP7B1, increased about 5-fold between infancy and adolescence whereas the activities in kidney microsomes decreased at least 10-fold. In conclusion, the results indicate that the expression of CYP27A1 and 3 ␤ -hydroxy-⌬ 5 -C 27 -steroid dehydrogenase are similar in livers of newborn and 6-month-old pigs whereas the levels of CYP7A1 increase. The finding that the levels of CYP7B1 increase with age in the liver but decrease in the kidney suggest a tissue-specific developmental regulation of CYP7B1. The age-dependent variation in the liver and kidney suggests that hormonal factors are involved in the regulation of CYP7B1. -Norlin, M. Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences.

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Section: Hepatic Mitochondrial Cyp27a1mentioning

confidence: 64%

Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences

Norlin

2002

Journal of Lipid Research

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“…cDNAs encoding Pak1 were subcloned into the epitope-tagged expression vector pJ3M ( Sells and Chernoff, 1995 ) and then subcloned into a modified version of pCMV5 ( Andersson et al, 1989 ). For some experiments, an amino-terminal Myc epitope-tagged Pak1 was used.…”

Section: Methodsmentioning

confidence: 99%

Periostin/Filamin-A: A Candidate Central Regulatory Axis for Valve Fibrogenesis and Matrix Compaction

Misra

Ghatak

Rodríguez

et al. 2021

Front. Cell Dev. Biol.

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BackgroundDiscoveries in the identification of transcription factors, growth factors and extracellular signaling molecules have led to the detection of downstream targets that modulate valvular tissue organization that occurs during development, aging, or disease. Among these, matricellular protein, periostin, and cytoskeletal protein filamin A are highly expressed in developing heart valves. The phenotype of periostin null indicates that periostin promotes migration, survival, and differentiation of valve interstitial cushion cells into fibroblastic lineages necessary for postnatal valve remodeling/maturation. Genetically inhibiting filamin A expression in valve interstitial cushion cells mirrored the phenotype of periostin nulls, suggesting a molecular interaction between these two proteins resulted in poorly remodeled valve leaflets that might be prone to myxomatous over time. We examined whether filamin A has a cross-talk with periostin/signaling that promotes remodeling of postnatal heart valves into mature leaflets.ResultsWe have previously shown that periostin/integrin-β1 regulates Pak1 activation; here, we revealed that the strong interaction between Pak1 and filamin A proteins was only observed after stimulation of VICs with periostin; suggesting that periostin/integrin-β-mediated interaction between FLNA and Pak1 may have a functional role in vivo. We found that FLNA phosphorylation (S2152) is activated by Pak1, and this interaction was observed after stimulation with periostin/integrin-β1/Cdc42/Rac1 signaling; consequently, FLNA binding to Pak1 stimulates its kinase activity. Patients with floppy and/or prolapsed mitral valves, when genetically screened, were found to have point mutations in the filamin A gene at P637Q and G288R. Expression of either of these filamin A mutants failed to increase the magnitude of filamin A (S2152) expression, Pak1-kinase activity, actin polymerization, and differentiation of VICs into mature mitral valve leaflets in response to periostin signaling.ConclusionPN-stimulated bidirectional interaction between activated FLNA and Pak1 is essential for actin cytoskeletal reorganization and the differentiation of immature VICs into mature valve leaflets.

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“…The 3 Ј antisense primer contained sequences that hybridized to DNA corresponding to amino acids 291 -300 of apoB followed by the 8-amino acid FLAG epitope, a termination codon, and an Xba I restriction site. The PCR product was cloned into the Eco RI (5 Ј ) and Xba I (3 Ј ) sites of expression plasmid pCMV5 (21). Correct sequence and orientation of the MTP and apoB-6.6F plasmids was verified by automated DNA sequencing.…”

Section: Plasmid Constructionmentioning

confidence: 99%

Lipoprotein assembly capacity of the mammary tumor-derived cell line C127 is due to the expression of functional microsomal triglyceride transfer protein

Sellers

Shelness

2001

Journal of Lipid Research

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C127, a murine mammary tumor-derived cell line, is capable of lipidating and secreting apolipoprotein B-41 (apoB-41) in the apparent absence of microsomal triglyceride transfer protein (MTP). Using a semiquantitative reverse transcriptase-coupled polymerase chain reaction, mouse MTP mRNA was detected in C127 cells at ϳ 10-20% of the relative abundance of human MTP in HepG2 cells. Radiolabeling of C127 cells with [ 35 S]methionine and [ 35 S]cysteine followed by immunoprecipitation with anti-MTP antibodies identified a band with an electrophoretic mobility identical to that of authentic mouse MTP. Cotransfection of apoB-41 and the MTP 97-kDa subunit in C127 cells enhanced apoB secretion by ϳ 5-fold relative to apoB-41 transfection alone, suggesting that MTP is limiting in these cells. To establish that MTP expression is responsible for apoBcontaining lipoprotein assembly in C127 cells, the effects of the MTP inhibitor BMS-200150 were examined. Secretion of apoB-41 by C127 cells was inhibited to the same extent observed in COS-1 cells cotransfected with apoB-41 and MTP. These results suggest that low MTP expression, and not the expression or overexpression of another known or novel factor(s), is responsible for apoB assembly and secretion in C127 cells and further supports the essential nature of MTP in the biogenesis of apoB-containing lipoproteins. -Sellers, J. A., and G. S. Shelness. Lipoprotein assembly capacity of the mammary tumor-derived cell line C127 is due to the expression of functional microsomal triglyceride transfer protein.

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Cloning, structure, and expression of the mitochondrial cytochrome P-450 sterol 26-hydroxylase, a bile acid biosynthetic enzyme

Cited by 1,184 publications

References 44 publications

Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences

Expression of key enzymes in bile acid biosynthesis during development: CYP7B1-mediated activities show tissue-specific differences

Periostin/Filamin-A: A Candidate Central Regulatory Axis for Valve Fibrogenesis and Matrix Compaction

Lipoprotein assembly capacity of the mammary tumor-derived cell line C127 is due to the expression of functional microsomal triglyceride transfer protein

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