Cloning and pretranslational hormonal regulation of testosterone 16α-hydroxylase (P-45016α) in male rat liver

1988 ◽  
Vol 118 (2) ◽  
pp. 314-320 ◽  
Author(s):  
Anders Ström ◽  
Agneta Mode ◽  
Peter Zaphiropoulos ◽  
Anne-Gerd Nilsson ◽  
Edward Morgan ◽  
...  

Abstract. cDNA clones for P-45016α were isolated from a male liver λgt 11 expression library using antibodies against P-45016α. The clones encompassed 1633 and 1791 bp, respectively. The latter clone contained the whole coding sequence. The 20 deduced NH2-terminal amino acids were identical to those of P-450h and the cDNA sequence was in complete agreement with that of P-450 (M-1). Northern blots showed that P-45016α in the rat liver is pretranslationally regulated by the growth hormone secretory pattern. Southern blots indicated that few genes belong to the same P-450 gene family as P-45016α.

1989 ◽  
Vol 264 (3) ◽  
pp. 695-701 ◽  
Author(s):  
K J Fisher ◽  
N N Aronson

cDNA clones for alpha-L-fucosidase were isolated from a rat liver lambda gt11 expression library by using both monospecific polyclonal antibodies against the affinity-purified enzyme and biotinylated rat liver fucosidase cDNA sequences as probes. The largest clone, lambda FC9, contained a 1522 bp full-length cDNA insert (FC9) that encoded the 434-amino acid-residue subunit (Mr 50439) of rat liver alpha-L-fucosidase. A putative signal peptide 28 amino acid residues in length preceded the sequence for the mature protein. In addition, FC9 specified for 11 nucleotide residues of 5′ untranslated sequence, 78 nucleotide residues of 3′ untranslated sequence and a poly(A) tail. The deduced amino acid sequence from FC9 in conjunction with the experimentally determined N-terminus of the mature enzyme suggested that rat liver fucosidase did not contain a pro-segment. However, there was the possibility of limited N-terminal processing (one to five amino acid residues) having occurred after removal of the predicted signal peptide. Amino acid sequences deduced from FC9 were co-linear with amino acid sequences measured at the N-terminus of purified fucosidase and on two of its CNBr-cleavage peptides. An unusual aspect of rat liver alpha-L-fucosidase protein structure obtained from the FC9 data was its high content of tryptophan (6%). The coding sequence from FC9 showed 82% sequence identity with that from a previously reported incomplete human fucosidase sequence [O'Brien, Willems, Fukushima, de Wet, Darby, DiCioccio, Fowler & Shows, (1987) Enzyme 38, 45-53].


1988 ◽  
Vol 8 (5) ◽  
pp. 401-406 ◽  
Author(s):  
C. D. Kelly ◽  
N. D. Carter ◽  
S. Jeffery ◽  
Y. H. Edwards

cDNA clones for rat muscle carbonic anhydrase III have been isolated from a λ gt-11 library and sequenced. Comparison with human CAIII cDNA showed about 90% homology to rat. The rat clones were used to estimate mRNA from liver and muscle on Northern blots and showed that the sexual dimorphism of CAIII in rat liver relates to a difference in mRNA levels.


1986 ◽  
Vol 6 (6) ◽  
pp. 527-534
Author(s):  
Colin Watts

cDNA clones for the major rat liver asialoglycoprotein (ASGP) receptor were isolated from a phage λgtl 1 library using synthetic oligonucleotide probes corresponding to two regions of the protein sequence. The longest clone obtained encoded all but the first 11 codons of the receptor. The cDNA was completed with synthetic oligonucleotides and was used to direct the synthesis of mRNA for the receptor in vitro. Subsequent translation in a wheat germ lysate produced authentic ASGP receptor which assembled correctly into microsomal membranes.


1998 ◽  
Vol 335 (3) ◽  
pp. 619-630 ◽  
Author(s):  
Philip J. SHERRATT ◽  
Margaret M. MANSON ◽  
Anne M. THOMSON ◽  
Erna A. M. HISSINK ◽  
Gordon E. NEAL ◽  
...  

A characteristic feature of the class Theta glutathione S-transferase (GST) T1-1 is its ability to activate dichloromethane and dibromoethane by catalysing the formation of mutagenic conjugates. The level of the GSTT1 subunit within tissues is an important determinant of susceptibility to the carcinogenic effects of these dihaloalkanes. In the present study it is demonstrated that hepatic GST activity towards these compounds can be elevated significantly in female and male Fischer-344 rats by feeding these animals on diets supplemented with cancer chemopreventive agents. Immunoblotting experiments showed that increased activity towards the dihaloalkanes is associated with elevated levels of the GSTT1 subunit in rat liver. Sex-specific effects were observed in the induction of GSTT1 protein. Amongst the chemopreventive agents tested, indole-3-carbinol proved to be the most potent inducer of hepatic GSTT1 in male rats (6.2-fold), whereas coumarin was the most potent inducer of this subunit in the livers of female rats (3.5-fold). Phenobarbital showed significant induction of GSTT1 only in male rat liver and had little effect in female rat liver. Western blotting showed that class Alpha, Mu and Pi GST subunits are not co-ordinately induced with GSTT1, indicating that the expression of GSTT1 is determined, at least in part, by mechanisms distinct from those that regulate levels of other transferases. The increase in amount of hepatic GSTT1 protein was also reflected by an increase in the steady-state level of mRNA in response to treatment with chemopreventive agents and model inducers. Immunohistochemical detection of GSTT1 in rat liver supported the Western blotting data, but showed, in addition to cytoplasmic staining, significant nuclear localization of the enzyme in hepatocytes from some treated animals, including those fed on an oltipraz-containing diet. Significantly, the hepatic level of cytochrome P-450 2E1, an enzyme which offers a detoxification pathway for dihaloalkanes, was unchanged by the various inducing agents studied. It is concluded that the induction of GSTT1 by dietary components and its localization within cells are important factors that should be considered when assessing the risk dihaloalkanes pose to human health.


Endocrinology ◽  
1984 ◽  
Vol 115 (2) ◽  
pp. 672-680 ◽  
Author(s):  
GUNNAR NORSTEDT ◽  
GÖRAN ANDERSSON ◽  
JAN-ÅKE GUSTAFSSON
Keyword(s):  

1987 ◽  
Vol 7 (5) ◽  
pp. 1841-1847
Author(s):  
M McPhaul ◽  
P Berg

The asialoglycoprotein receptor (ASGP-R) from rat liver contains the following three distinct protein species when it is analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis: RHL1 (42 kilodaltons), RHL2 (49 kilodaltons), and RHL3 (54 kilodaltons). In this paper we describe the isolation of cDNA clones encoding RHL1 and RHL2 from a cDNA library constructed from rat liver mRNA. A comparison of the predicted coding sequence for RHL2 with that for RHL1 showed that these sequences are highly homologous. The library also contained numerous cDNA clones for both RHL1 and RHL2 that were derived from unspliced precursor mRNAs. Differential splicing at the 5' end of the RHL1 transcript was inferred from the finding that two different types of RHL1 cDNA were identified, each having a different 5' terminus.


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