Isolation and in vitro translation of mRNA from the calf abomasal mucosa and identification of an mRNA coding for a precursor of prochymosin

1984 ◽  
Vol 51 (1) ◽  
pp. 79-89
Author(s):  
Bruce H. Nicholson ◽  
Peter Jones

SummaryThe mRNA coding for prochymosin (prorennin) has been partly purified from calf abomasum. The in vitro translation products of the total polyadenylated RNA show a major band on gel electrophoresis which reacts with antibody raised against purified chymosin. The mol. wt of 43000 is higher than expected from the reported amino acid sequence and would correspond to prochymosin with an unprocessed signal sequence of ∼ 17 amino acids. The synthesis of chymosin mRNA is age-related, and ceases by 3 months even in milk-fed calves.

2001 ◽  
Vol 183 (6) ◽  
pp. 1954-1960 ◽  
Author(s):  
Grit Zarnt ◽  
Thomas Schräder ◽  
Jan R. Andreesen

ABSTRACT The quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (THFA-DH) from Ralstonia eutropha strain Bo was investigated for its catalytic properties. The apparentk cat/Km andK i values for several substrates were determined using ferricyanide as an artificial electron acceptor. The highest catalytic efficiency was obtained with n-pentanol exhibiting a k cat/Km value of 788 × 104 M−1 s−1. The enzyme showed substrate inhibition kinetics for most of the alcohols and aldehydes investigated. A stereoselective oxidation of chiral alcohols with a varying enantiomeric preference was observed. Initial rate studies using ethanol and acetaldehyde as substrates revealed that a ping-pong mechanism can be assumed for in vitro catalysis of THFA-DH. The gene encoding THFA-DH from R. eutropha strain Bo (tfaA) has been cloned and sequenced. The derived amino acid sequence showed an identity of up to 67% to the sequence of various quinoprotein and quinohemoprotein dehydrogenases. A comparison of the deduced sequence with the N-terminal amino acid sequence previously determined by Edman degradation analysis suggested the presence of a signal sequence of 27 residues. The primary structure of TfaA indicated that the protein has a tertiary structure quite similar to those of other quinoprotein dehydrogenases.


1987 ◽  
Vol 104 (6) ◽  
pp. 1705-1714 ◽  
Author(s):  
J Finidori ◽  
L Rizzolo ◽  
A Gonzalez ◽  
G Kreibich ◽  
M Adesnik ◽  
...  

The co-translational insertion of polypeptides into endoplasmic reticulum membranes may be initiated by cleavable amino-terminal insertion signals, as well as by permanent insertion signals located at the amino-terminus or in the interior of a polypeptide. To determine whether the location of an insertion signal within a polypeptide affects its function, possibly by affecting its capacity to achieve a loop disposition during its insertion into the membrane, we have investigated the functional properties of relocated insertion signals within chimeric polypeptides. An artificial gene encoding a polypeptide (THA-HA), consisting of the luminal domain of the influenza hemagglutinin preceded by its amino-terminal signal sequence and linked at its carboxy-terminus to an intact prehemagglutinin polypeptide, was constructed and expressed in in vitro translation systems containing microsomal membranes. As expected, the amino-terminal signal initiated co-translational insertion of the hybrid polypeptide into the membranes. The second, identical, interiorized signal, however, was not recognized by the signal peptidase and was translocated across the membrane. The failure of the interiorized signal to be cleaved may be attributed to the fact that it enters the membrane as part of a translocating polypeptide and therefore cannot achieve the loop configuration that is thought to be adopted by signals that initiate insertion. The finding that the interiorized signal did not halt translocation of downstream sequences, even though it contains a hydrophobic region and must enter the membrane in the same configuration as natural stop-transfer signals, indicates that the HA insertion signal lacks essential elements of halt transfer signals that makes the latter effective membrane-anchoring domains. When the amino-terminal insertion signal of the THA-HA chimera was deleted, the interior signal was incapable of mediating insertion, probably because of steric hindrance by the folded preceding portions of the chimera. Several chimeras were constructed in which the interiorized signal was preceded by polypeptide segments of various lengths. A signal preceded by a segment of 111 amino acids was also incapable of initiating insertion, but insertion took place normally when the segment preceding the signal was only 11-amino acids long.(ABSTRACT TRUNCATED AT 400 WORDS)


1995 ◽  
Vol 62 (2) ◽  
pp. 297-309 ◽  
Author(s):  
Francesco Addeo ◽  
Giuseppina Garro ◽  
Nunziatina Intorcia ◽  
Luisa Pellegrino ◽  
Pierpaolo Resmini ◽  
...  

SUMMARYThe whole N fraction of six samples of hard and semi-hard pressed cheeses was analysed using PAGE, polyacrylamide gel isoelectric focusing and immuno blotting with polyclonal antibodies against β- and αs1-casein. The origin of some electrophoretic bands corresponding to peptides produced from the enzymic degradation of the casein fractions was established. A number of these peptides were also present in the in vitro hydrolysates of casein with plasmin and chymosin. Thus, it was also possible to determine which casein was the source of each peptide and which enzymes were active in cheese. Compared with the traditional Coomassie staining procedures, immunoblotting is more sensitive and specific, making the interpretation of each electrophoretic profile easy. Thus, it was also possible to obtain a clear picture of the state of each casein fraction in a cheese variety. Two main peptides were isolated from the pH 4·6-insoluble N fraction of Parmigiano-Reggiano using DEAE-cellulose chromatography and identified, from the amino acid sequence of the N- and C-terminal ends, as γ3-casein (β-casein(f108–209)) and αs1-PL1 (αs1-casein(f80–199)). In both cases, a Lys–X bond was hydrolysed, indicating the action of a trypsin-like enzyme in β- and αs1-casein hydrolysis during the ripening of this variety of hard pressed cheese.


1988 ◽  
Vol 167 (6) ◽  
pp. 1883-1893 ◽  
Author(s):  
K Matsushima ◽  
K Morishita ◽  
T Yoshimura ◽  
S Lavu ◽  
Y Kobayashi ◽  
...  

The cDNA coding for human monocyte-derived neutrophil-specific chemotactic factor (MDNCF) was cloned from LPS-stimulated human monocyte mRNA. The cDNA sequence codes for a polypeptide consisting of 99 amino acids, including a putative signal sequence. Comparison of the deduced amino acid sequence with the NH2-terminal amino acid sequence of natural MDNCF shows that the mature functional protein comprises 72 amino acids, beginning with serine at residue 28. The deduced amino acid sequence shows striking similarity to several platelet-derived factors, a v-src-induced protein, a growth-regulated gene product (gro), and an IFN-gamma inducible protein. The availability of the MDNCF cDNA enabled us to use it as a probe to identify inducers of MDNCF mRNA expression in human PBMC. MDNCF mRNA was increased greater than 10-fold within 1 h after stimulation with LPS, IL-1, or TNF, but not by IFN-gamma, IFN-alpha, or IL-2. Furthermore, we also determined that LPS, IL-1, and TNF stimulated the mononuclear cells to produce biologically active MDNCF. This observation may account for the in vivo capacity of IL-1 and TNF to induce netrophil infiltrates.


2008 ◽  
Vol 410 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Rachael A. Dunlop ◽  
Roger T. Dean ◽  
Kenneth J. Rodgers

Oxidized protein deposition and accumulation have been implicated in the aetiology of a wide variety of age-related pathologies. Protein oxidation in vivo commonly results in the in situ modification of amino acid side chains, generating new oxidized amino acid residues in proteins. We have demonstrated previously that certain oxidized amino acids can be (mis)incorporated into cell proteins in vitro via protein synthesis. In the present study, we show that incorporation of o- and m-tyrosine resulted in increased protein catabolism, whereas dopa incorporation generated proteins that were inefficiently degraded by cells. Incorporation of higher levels of L-dopa into proteins resulted in an increase in the activity of lysosomal cathepsins, increased autofluorescence and the generation of high-molecular-mass SDS-stable complexes, indicative of protein aggregation. These effects were due to proteins containing incorporated L-dopa, since they were not seen with the stereoisomer D-dopa, which enters the cell and generates the same reactive species as L-dopa, but cannot be incorporated into proteins. The present study highlights how the nature of the oxidative modification to the protein can determine the efficiency of its removal from the cell by proteolysis. Protection against the generation of dopa and other species that promote resistance to proteolysis might prove to be critical in preventing toxicity from oxidative stress in pathologies associated with protein deposition, such as atherosclerosis, Alzheimer's disease and Parkinson's disease.


1992 ◽  
Vol 118 (2) ◽  
pp. 481-490 ◽  
Author(s):  
G H Miao ◽  
Z Hong ◽  
D P Verma

Soybean nodulin-26, a homologue of bovine eye lens major intrinsic protein (MIP-26), is an integral protein of the peribacteroid membrane in symbiotic root nodules. It comprises 271 amino acids with six potential transmembrane domains and lacks an amino-terminal signal sequence. A full-length nodulin-26 cDNA and its various deletion derivatives were transcribed in vitro after linking them to bacteriophage T3 promoter. In vitro translation of these transcripts in a rabbit reticulocyte lysate, in the presence or absence of canine pancreatic microsomal membranes, suggested that nodulin-26 is cotranslationally inserted into the microsomes without a cleavable signal peptide. The first two transmembrane domains (103 amino acids) of the protein are sufficient for microsomal membrane insertion. Membrane-translocated nodulin-26 binds to Con-A and is sensitive to endoglycosidase-H treatment, suggesting that it is glycosylated. Native nodulin-26 from root nodules retains its sugar moiety as it, too, binds to Con-A. Chemical cleavage mapping at cysteine residues, a trypsin protection assay, and the Con-A binding affinity of nodulin-26 suggested that both the NH2 and COOH termini of this protein are on the cytoplasmic surface of the peribacteroid membrane, while the glycosidic residue is on the surface of the membrane facing the bacteroids. In vitro phosphorylation experiments showed that nodulin-26 is a major phosphorylated protein in the peribacteroid membrane. This phosphorylation is mediated by a Ca(2+)-dependent, calmodulin-independent protein kinase located in the peribacteriod membrane. Externally supplied acid phosphatase dephosphorylates this protein, but alkaline phosphatase does not. Based on its homology with several eukaryotic and prokaryotic channel-type membrane proteins, nodulin-26 may form a channel translocating specific molecules to the bacteroids during endosymbiosis in legume plants.


1990 ◽  
Vol 4 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Y. Kato ◽  
T. Hirai ◽  
T. Kato

ABSTRACT Porcine prolactin cDNA clones were screened using antiserum against ovine prolactin from a cDNA library of porcine anterior pituitary, and their nucleotide sequences were determined by the chain-termination method. The nucleotide sequence of the 5′ untranslated region and part of the signal peptide region were determined by direct RNA sequencing with reverse transcriptase. The composite sequence of 957 nucleotides showed a signal sequence of 30 amino acids and a further 199 amino acids corresponding to the mature prolactin molecule. The predicted sequence confirmed the amino acid sequence determined previously by direct protein analysis, except for one amide form at residue 122 (Gln instead of the reported Glu). Northern blot analysis showed that the length of the porcine prolactin mRNA was about 1·1 kb. The porcine prolactin amino acid sequence showed 81, 80, 64, 62, 80 and 31% homology with human, bovine, rat, mouse, chick and salmon forms respectively. The identical amino acid residues showed marked clustering in four domains, two of which are highly conserved throughout a wide range of species. The hydropathy and secondary structure of porcine prolactin were analysed and compared with those of porcine GH, which shares the same ancestral gene. The two highly conserved regions of both hormones showed similar hydrophilicity, and the predicted secondary structures indicated that these regions in each hormone form different structures with differences in extension of the hydrophilic residues outside the molecule.


1998 ◽  
Vol 329 (2) ◽  
pp. 313-319 ◽  
Author(s):  
Danuta MAKSEL ◽  
Andrzej GURANOWSKI ◽  
C. Steven ILGOUTZ ◽  
Arthur MOIR ◽  
G. Michael BLACKBURN ◽  
...  

The first isolation, cloning and expression of cDNA encoding an asymmetric diadenosine 5ʹ,5‴P1,P4-tetraphosphate pyrophosphohydrolase (Ap4A hydrolase) from a higher plant is described. Ap4A hydrolase protein was purified from seeds of both Lupinus luteus and Lupinus angustifolius and partially sequenced. The Ap4A hydrolase cDNA was cloned from L. angustifolius cotyledonary polyadenylated RNA using reverse transcription and PCR with primers based on the amino acid sequence. The cDNA encoded a protein of 199 amino acids, molecular mass 22982 Da. When expressed in Escherichia coli fused to a maltose-binding protein, the enzyme catalysed asymmetric cleavage of Ap4A to AMP and ATP which was inhibited at concentrations of F- as low as 3 μM. These are properties characteristic of Ap4A hydrolase (asymmetrical) (EC 3.6.1.17). Comparison of the Ap4A hydrolase sequences derived from the four known cDNAs from pig, human, lupin and fission yeast showed that, like the mammalian hydrolase, the lupin enzyme possesses a Mut T motif but no other significant similarities. No sequence similarity to the human fragile histidine triad protein, as found in the Ap4A hydrolase from Schizosaccharomyces pombe, was detected in the Ap4A hydrolase from lupin.


1987 ◽  
Vol 104 (4) ◽  
pp. 855-863 ◽  
Author(s):  
V Harnik-Ort ◽  
K Prakash ◽  
E Marcantonio ◽  
DR Colman ◽  
MG Rosenfeld ◽  
...  

Ribophorins I and II are two transmembrane glycoproteins that are characteristic of the rough endoplasmic reticulum and are thought to be part of the apparatus that affects the co-translational translocation of polypeptides synthesized on membrane-bound polysomes. A ribophorin I cDNA clone containing a 0.6-kb insert was isolated from a rat liver lambda gtll cDNA library by immunoscreening with specific antibodies. This cDNA was used to isolate a clone (2.3 kb) from a rat brain lambda gtll cDNA library that contains the entire ribophorin I coding sequence. SP6 RNA transcripts of the insert in this clone directed the in vitro synthesis of a polypeptide of the expected size that was immunoprecipitated with anti-ribophorin I antibodies. When synthesized in the presence of microsomes, this polypeptide, like the translation product of the natural ribophorin I mRNA, underwent membrane insertion, signal cleavage, and co-translational glycosylation. The complete amino acid sequence of the polypeptide encoded in the cDNA insert was derived from the nucleotide sequence and found to contain a segment that corresponds to a partial amino terminal sequence of ribophorin I that was obtained by Edman degradation. This confirmed the identity of the cDNA clone and established that ribophorin I contains 583 amino acids and is synthesized with a cleavable amino terminal insertion signal of 22 residues. Analysis of the amino acid sequence of ribophorin I suggested that the polypeptide has a simple transmembrane disposition with a rather hydrophilic carboxy terminal segment of 150 amino acids exposed on the cytoplasmic face of the membrane, and a luminal domain of 414 amino acids containing three potential N-glycosylation sites. Hybridization measurements using the cloned cDNA as a probe showed that ribophorin I mRNA levels increase fourfold 15 h after partial hepatectomy, in confirmation of measurements made by in vitro translation of liver mRNA. Southern blot analysis of rat genomic DNA suggests that there is a single copy of the ribophorin I gene in the haploid rat genome.


1986 ◽  
Vol 6 (7) ◽  
pp. 2655-2662
Author(s):  
M Huleihel ◽  
M Goldsborough ◽  
J Cleveland ◽  
M Gunnell ◽  
T Bonner ◽  
...  

A 1.6-kilobase cDNA (A-raf) has been isolated from a murine spleen cDNA library which encodes part of a protein related to the raf oncogene. Its amino acid sequence has 85% homology to raf in a central portion of 100 amino acids. In contrast to raf, A-raf shows a highly restricted tissue distribution of expression, with highest levels observed in epididymis, followed by intestine. When incorporated into a retrovirus, the resulting gag-A-raf fusion gene causes transformation in vitro and induces tumors in newborn mice. Thus, A-raf represents a new proto-oncogene. Transformation by A-raf is independent of ras gene function, as is the case for raf and mos but not other oncogenes.


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