Anti-Mouse GPI-PLD Antisera Highlight Structural Differences between Murine and Bovine GPI-PLDs

2003 ◽  
Vol 384 (12) ◽  
pp. 1575-1582 ◽  
Author(s):  
P. Gregory ◽  
A. Ziemiecki ◽  
G. Zürcher ◽  
U. Brodbeck ◽  
P. Bütikofer

AbstractDespite its well characterised biochemistry, the physiological role of glycosylphosphatidylinositolspecific phospholipase D (GPIPLD) is unknown. Most of the previous studies investigating the distribution of GPI-PLD have focused on the human and bovine forms of the enzyme. Studies on mouse GPI-PLD are rare, partly due to the lack of a specific antimouse GPI-PLD antibody, but also due to the apparent low reactivity of existing antibodies to rodent GPI-PLDs. Here we describe the isolation of a mouse liver cDNA, the construction and expression of a recombinant enzyme and the generation of an affinitypurified rabbit antimouse GPI-PLD antiserum. The antibody shows good reactivity to partially purified murine and purified bovine GPI-PLD. In contrast, a rat antibovine GPI-PLD antibody shows no reactivity with the mouse enzyme and the two antibodies recognise different proteolytic fragments of the bovine enzyme. Comparison between the rodent, bovine and human enzymes indicates that small changes in the amino acid sequence of a short peptide in the mouse and bovine GPI-PLDs may contribute to the different reactivities of the two antisera. We discuss the implications of these results and stress the importance of antibody selection while investigating GPI-PLD in the mouse.

2019 ◽  
Vol 20 (13) ◽  
pp. 3314 ◽  
Author(s):  
Janah ◽  
Kjeldsen ◽  
Galsgaard ◽  
Winther-Sørensen ◽  
Stojanovska ◽  
...  

Hundred years after the discovery of glucagon, its biology remains enigmatic. Accurate measurement of glucagon has been essential for uncovering its pathological hypersecretion that underlies various metabolic diseases including not only diabetes and liver diseases but also cancers (glucagonomas). The suggested key role of glucagon in the development of diabetes has been termed the bihormonal hypothesis. However, studying tissue-specific knockout of the glucagon receptor has revealed that the physiological role of glucagon may extend beyond blood-glucose regulation. Decades ago, animal and human studies reported an important role of glucagon in amino acid metabolism through ureagenesis. Using modern technologies such as metabolomic profiling, knowledge about the effects of glucagon on amino acid metabolism has been expanded and the mechanisms involved further delineated. Glucagon receptor antagonists have indirectly put focus on glucagon’s potential role in lipid metabolism, as individuals treated with these antagonists showed dyslipidemia and increased hepatic fat. One emerging field in glucagon biology now seems to include the concept of hepatic glucagon resistance. Here, we discuss the roles of glucagon in glucose homeostasis, amino acid metabolism, and lipid metabolism and present speculations on the molecular pathways causing and associating with postulated hepatic glucagon resistance.


1994 ◽  
Vol 180 (1) ◽  
pp. 319-327 ◽  
Author(s):  
M C Pessolani ◽  
D R Smith ◽  
B Rivoire ◽  
J McCormick ◽  
S A Hefta ◽  
...  

The study of tissue-derived Mycobacterium leprae provides insights to the immunopathology of leprosy and helps identify broad molecular features necessary for mycobacterial parasitism. A major membrane protein (MMP-II) of in vivo-derived M. leprae previously recognized (Hunter, S.W., B. Rivoire, V. Mehra, B.R. Bloom, and P.J. Brennan. 1990. J. Biol. Chem. 265:14065) was purified from extracts of the organism and partial amino acid sequence obtained. This information allowed recognition, within one of the cosmids that encompass the entire M. leprae genome, of a complete gene, bfr, encoding a protein of subunit size 18.2 kD. The amino acid sequence deduced from the major membrane protein II (MMP-II) gene revealed considerable homology to several bacterioferritins. Analysis of the native protein demonstrated the iron content, absorption spectrum, and large native molecular mass (380 kD) of several known bacterioferritins. The ferroxidase-center residues typical of ferritins were conserved in the M. leprae product. Oligonucleotides derived from the amino acid sequence of M. leprae bacterioferritin enabled amplification of much of the MMP-II gene and the detection of homologous sequences in Mycobacterium paratuberculosis, Mycobacterium avium, Mycobacterium tuberculosis, Mycobacterium intracellulare, and Mycobacterium scrofulaceum. The role of this iron-rich protein in the virulence of M. leprae is discussed.


1991 ◽  
Vol 276 (2) ◽  
pp. 461-469 ◽  
Author(s):  
L I McLellan ◽  
L A Kerr ◽  
A D Cronshaw ◽  
J D Hayes

Liver cytosol from mice fed on a normal diet contains Alpha-class glutathione S-transferase (GST) subunits of Mr 25,800, Mu-class GST subunits of Mr 26,400 and Pi-class GST subunits of Mr 24,800. Feeding female mice with a diet containing the anticarcinogenic antioxidant butylated hydroxyanisole (BHA) causes induction of the constitutively expressed Mu-class and Pi-class subunits. BHA also induces an Alpha-class GST comprising subunits of Mr 25,600, which is not expressed at detectable levels in normal mouse liver [McLellan & Hayes (1989) Biochem. J. 263, 393-402]. Data are now presented that show that administration of the anticarcinogen beta-naphthoflavone (BNF), like BHA, induces the Alpha-class 25,600-Mr subunits but not the constitutive Alpha-class GST with subunits of Mr 25,800. The effects of BNF on expression of hepatic GST were studied in both DBA/2 and C57BL/6 mice; these studies revealed a preferential induction of the Alpha-class 25,600-Mr subunits and of the Pi-class 24,800-Mr subunits in those mice in possession of a functional Ah receptor. The BHA/BNF-inducible Alpha-class GST can be resolved into two separate, non-interconvertible peaks by reverse-phase h.p.l.c. Automated amino acid sequence analysis of CNBr-derived peptides from each of these h.p.l.c.-purified peaks showed that the peaks contained at least two very similar subunits. These have been named Ya1 and Ya2. The amino acid sequence of the Ya1 subunit was compared with sequences deduced from a genomic clone, lambda mYa1 (Daniel, Sharon, Tichauer & Sarid (1987) DNA 6, 317-324], and a cDNA clone, pGT41 [Pearson, Reinhart, Sisk, Anderson & Adler (1988) J. Biol. Chem. 263, 13324-13332]. Our data suggest that the Ya1 subunit represents the subunit encoded by the genomic clone, lambda mYa1. Sequence analysis of the constitutive Alpha-class Ya3 subunit (Mr 25,800) shows that, although it is a member of the same gene family as the Ya1 and Ya2 subunits, it represents a distinct sub-family of Alpha-class GST, containing subunits that are more similar to rat Yc. Our data indicate that, of these Alpha-class GST subunits, the two with Mr 25,600 (Ya1 and Ya2) are selectively induced by BHA or BNF in mouse liver; neither BHA nor BNF induces significantly the GST subunit with Mr 25,800 (Ya3).


1999 ◽  
Vol 181 (6) ◽  
pp. 1958-1962 ◽  
Author(s):  
Jørgen Sauer ◽  
Per Nygaard

ABSTRACT The hpt gene from the archaeon Methanobacterium thermoautotrophicum, encoding hypoxanthine (guanine) phosphoribosyltransferase, was cloned by functional complementation into Escherichia coli. The hpt-encoded amino acid sequence is most similar to adenine phosphoribosyltransferases, but the encoded enzyme has activity only with hypoxanthine and guanine. The synthesis of the recombinant enzyme is apparently limited by the presence of the rare arginine codons AGA and AGG and the rare isoleucine AUA codon on the hpt gene. The recombinant enzyme was purified to apparent homogeneity.


Parasitology ◽  
2016 ◽  
Vol 143 (5) ◽  
pp. 576-587 ◽  
Author(s):  
NATALIA MALLO ◽  
JESÚS LAMAS ◽  
ANA-PAULA DEFELIPE ◽  
MARIA-EUGENIA DECASTRO ◽  
ROSA-ANA SUEIRO ◽  
...  

SUMMARYH+-pyrophosphatases (H+-PPases) are integral membrane proteins that couple pyrophosphate energy to an electrochemical gradient across biological membranes and promote the acidification of cellular compartments. Eukaryotic organisms, essentially plants and protozoan parasites, contain various types of H+-PPases associated with vacuoles, plasma membrane and acidic Ca+2storage organelles called acidocalcisomes. We used Lysotracker Red DND-99 staining to identify two acidic cellular compartments in trophozoites of the marine scuticociliate parasitePhilasterides dicentrarchi: the phagocytic vacuoles and the alveolar sacs. The membranes of these compartments also contain H+-PPase, which may promote acidification of these cell structures. We also demonstrated for the first time that theP. dicentrarchiH+-PPase has two isoforms: H+-PPase 1 and 2. Isoform 2, which is probably generated by splicing, is located in the membranes of the alveolar sacs and has an amino acid motif recognized by the H+-PPase-specific antibody PABHK. The amino acid sequences of different isolates of this ciliate are highly conserved. Gene and protein expression in this isoform are significantly regulated by variations in salinity, indicating a possible physiological role of this enzyme and the alveolar sacs in osmoregulation and salt tolerance inP. dicentrarchi.


1992 ◽  
Vol 285 (1) ◽  
pp. 173-180 ◽  
Author(s):  
J D Hayes ◽  
D J Judah ◽  
G E Neal ◽  
T Nguyen

Resistance to the carcinogenic effects of aflatoxin B1 (AFB1) in the mouse is due to the constitutive expression of an Alpha-class glutathione S-transferase (GST), YcYc, with high detoxification activity towards AFB1-8,9-epoxide. A cDNA clone (pmusGST Yc) for a murine GST Yc polypeptide has been isolated. Sequencing has shown the cDNA insert of pmusGST Yc to be 922 bp in length, with an open reading frame of 663 bp that encodes a polypeptide of M(r) 25358. The primary structure of the murine GST Yc subunit predicted by pmusGST Yc is in complete agreement with the partial amino acid sequence of the aflatoxin-metabolizing mouse liver GST described previously [McLellan, Kerr, Cronshaw & Hayes (1991) Biochem. J. 276, 461-469]. A plasmid, termed pKK-musGST Yc, which permits the expression of the murine Yc subunit in Escherichia coli, has been constructed. The murine GST expressed in E. coli was purified and found to be catalytically active towards several GST substrates, including AFB1-8,9-epoxide. This enzyme was also found to possess electrophoretic and immunochemical properties closely similar to those of the GST Yc subunit from mouse liver. However, the GST synthesized in E. coli and the constitutive mouse liver Alpha-class GST exhibited small differences in their chromatographic behaviour during reverse-phase h.p.l.c. Automated Edman degradation revealed alanine to be the N-terminal amino acid in the GST Yc subunit expressed in E. coli, whereas the enzyme in mouse liver possesses a blocked N-terminus. Although sequencing showed that the purified Yc subunit from E. coli lacked the initiator methionine, the amino acid sequence obtained over the first eleven N-terminal residues agreed with that predicted from the cDNA clone, pmusGST Yc. Comparison of the deduced amino acid sequence of the mouse Yc polypeptide with the primary structures of the rat Alpha-class GST enzymes revealed that it is more closely related to the ethoxyquin-induced rat liver Yc2 subunit than to the constitutively expressed rat liver Yc1 subunit. The significance of the fact that both mouse Yc and rat Yc2 exhibit high catalytic activity towards AFB1-8,9-epoxide, whereas rat Yc1 possesses little activity towards this compound, is discussed in terms of structure/function.


Biochemistry ◽  
1990 ◽  
Vol 29 (37) ◽  
pp. 8713-8719 ◽  
Author(s):  
Roberta A. Parente ◽  
Laszlo Nadasdi ◽  
Nanda K. Subbarao ◽  
Francis C. Szoka

1995 ◽  
Vol 306 (2) ◽  
pp. 505-512 ◽  
Author(s):  
P Chan ◽  
J L Risler ◽  
G Raguenez ◽  
J P Salier

The inter-alpha-inhibitor (I alpha I) family is comprised of the plasma protease inhibitors I alpha I, inter-alpha-like inhibitor (I alpha LI), pre-alpha-inhibitor (P alpha I) and bikunin. I alpha I, I alpha LI and P alpha I are distinct assemblies of bikunin with one of three heavy (H) chains designated H1, H2 and H3. These H chains and bikunin are respectively encoded by a set of three H genes and an alpha 1-microglobulin/bikunin precursor (AMBP) gene. All four gene products undergo maturation steps from precursor polypeptides. The full-length cDNAs for the H1-, H2- and H3-chain precursors were cloned from a mouse liver cDNA library and sequenced. Extensive searches of amino acid sequence similarities to other proteins in databanks revealed (i) a highly significant similarity of the C-terminal sequence in the three H-chain precursors to the multicopper-binding domain in the group of multicopper oxidase proteins and (ii) the presence of von Willebrand type-A domains in the mature H chains. Amino acid sequence comparisons between the three mouse H1-, H2- and H3-chain precursors and their human counterparts allowed us to appraise the timing and order of occurrence of the three H-chain genes from a shared ancestor during mammalian evolution. Owing to a multiple alignment of the six mouse and human nucleotide sequences for these H-chain precursors, a reverse transcriptase PCR assay with degenerate oligonucleotides was designed, allowing us to (i) present evidence that no mRNAs for further H genes exist in mouse liver and (ii) demonstrate a previously undescribed transcription of the H2- and H3-chain mRNAs in mouse brain, which contrasts with the expression of all four, H1, H2, H3 and AMBP, mRNAs in liver.


Nature ◽  
1983 ◽  
Vol 304 (5925) ◽  
pp. 459-462 ◽  
Author(s):  
D. M. A. Evans ◽  
P. D. Minor ◽  
G. S. Schild ◽  
J. W. Almond

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