scholarly journals Cloning, sequencing and heterologous expression of a cDNA encoding pigeon liver carnitine acetyltransferase

1995 ◽  
Vol 305 (2) ◽  
pp. 439-444 ◽  
Author(s):  
T M Johnson ◽  
H P Kocher ◽  
R C Anderson ◽  
G M Nemecek

Two overlapping cDNA clones encoding pigeon liver carnitine acetyltransferase (EC 2.3.1.7) (CAT) were isolated from a pigeon liver lambda gt11 cDNA library by gene amplification using oligonucleotide primers based on the N-terminal amino acid sequence of the enzyme. The two clones, which represent the 5′ and 3′ ends of the gene, were spliced together to form a single cDNA construct containing the entire coding sequence for CAT, with an in-frame TGA stop codon 42 bases before the first ATG start site and a 3′-untranslated segment of 1057 bases. The largest open reading frame of 1942 nucleotides predicted a polypeptide of 627 amino acids and a molecular mass of 71.1 kDa. The N-terminus and four internal peptides from the amino acid sequence of pigeon breast muscle CAT were identified in the predicted sequence of the liver cDNA clone. The identity of the CAT cDNA was confirmed by heterologous expression of active recombinant CAT (rCAT) in insect cells using the baculovirus expression system. Western blots of rCAT from infected insect cell lysates and immunodetection with a rabbit anti-CAT polyclonal serum showed an immunoreactive protein band similar in size to native CAT from pigeon breast muscle. Like the native enzyme, rCAT was capable of acylating carnitine with a preference for small-chain acyl-CoAs of carbon chain lengths C2-C4.

Author(s):  
Qianqian Song ◽  
Zhixiu Wang ◽  
Hongliang Zhang ◽  
Xiangxiang Li ◽  
Yang Zhang ◽  
...  

Accumulating studies have indicated that the long-chain fatty acyl-CoA1 (ACSL1) gene is related to fat deposition and meat quality in mammals. However, few studies have investigated the relationship between ACSL1 and lipid deposition in ducks. To examine this, we assessed the physicochemical property, homologous alignment and phylogenetic analyses of the ACSL1 amino acid sequence using bioinformatics tools. The analysis indicated that the ACSL1 amino acid sequence varies in animals, and the duck ACSL1 protein is most closely related to that of chicken. Two SNP sites were identified at 1749 and 1905 bp of the coding region of ACSL1 by sequencing. Quantitative real-time PCR and western blotting were used to measure mRNA and protein levels in abdominal fat, breast muscle and liver tissue of Pekin duck (BD) and Cherry Valley duck (CD). mRNA and protein expression were significantly higher in BD than in CD in abdominal fat and liver tissue (P < 0.05). In breast muscle, the mRNA level of ACSL1 was also significantly higher in BD than in CD (P < 0.05), and protein expression in BD tended to be higher than that of CD. These results suggest that ACSL1 may contribute to lipid deposition and meat quality in ducks.


2003 ◽  
Vol 50 (1) ◽  
pp. 269-278
Author(s):  
Amr M Shabaan ◽  
Magdy M Mohamed ◽  
Mohga S Abdallah ◽  
Hayat M Ibrahim ◽  
Amr M Karim

Two Schistosoma mansoni cDNA clones 30S and 1H were identified by immunoscreening of sporocyst lambdagt11 library and by random sequencing of clones from lambdaZap libraries, respectively. Clone 30S was one of 30 clones identified by an antibody raised against tegument of 3-h schistosomules. The clone was found to encode an 81 amino-acid protein fragment. It was expressed in Escherichia coli as a fusion protein of calculated molecular mass of about 35 kDa with C-terminus of Schistosoma japonicum glutathione-S-transferase (Sj26; about 26 kDa). The recombinant fusion protein was specifically recognized by serum of rabbits immunized with irradiated cercariae. Clone 1H is one of 76 expressed sequence tags derived from an adult worm library. It encodes the complete sequence of a tegumental membrane protein, Sm13. The 104 amino-acid open reading frame encodes a protein with a calculated molecular mass of about 11.9 kDa. Clone 1H was expressed in E. coli as an insoluble fusion protein with Sj26 of about 40 kDa. In Western blots, the fusion protein was recognized by serum from rabbits vaccinated with irradiated cercariae but not by preimmune rabbit sera. The cloning, characterization and expression of those proteins are therefore potentially usefull for vaccine development.


Blood ◽  
1991 ◽  
Vol 78 (7) ◽  
pp. 1826-1833 ◽  
Author(s):  
LE Toothaker ◽  
DA Gonzalez ◽  
N Tung ◽  
RS Lemons ◽  
MM Le Beau ◽  
...  

Abstract We have isolated 5′ cDNA clones encoding a member of the cellular myosin heavy chain gene family from human leukocytes. The predicted amino acid sequence shows 93% identity to a chicken cellular myosin heavy chain, 76% to chicken smooth muscle, and 40% to human sarcomeric myosin heavy chain. The mRNA is expressed as a 7.4- to 7.9-kb doublet in many nonmuscle cells, and is upregulated in myeloid cell lines on induction from a proliferating to a differentiated state. Antisera raised against a peptide made from the predicted amino acid sequence specifically reacts with a 224-Kd polypeptide in leukocyte cell lines, and the protein is also upregulated during the induction of monocytic and granulocytic differentiation in these cells. The gene for this cellular myosin heavy chain maps to chromosome 22, bands q12.3-q13.1, demonstrating that it is not located in the previously described sarcomeric gene clusters on chromosomes 14 and 17. This cellular myosin heavy chain may be a major contractile protein responsible for movement in myeloid cell lines because no mRNA for sarcomeric myosin heavy chain is detected in these cells.


1992 ◽  
Vol 287 (2) ◽  
pp. 639-643 ◽  
Author(s):  
M S Reddy ◽  
L A Bobek ◽  
G G Haraszthy ◽  
A R Biesbrock ◽  
M J Levine

The low-molecular-mass human salivary mucin has at least two isoforms, MG2a and MG2b, that differ primarily in their sialic acid and fucose content. In this study, we characterize further these isoforms, particularly their peptide moieties. Trypsin digests of MG2a and MG2b yielded high- and low-molecular-mass glycopeptides following gel filtration on Sephacryl S-300. The larger glycopeptides from MG2a and MG2b had similar amino acid compositions and identical N-terminal sequences, suggesting common structural features between their peptides. An oligonucleotide probe generated from the amino acid sequence of the smaller glycopeptide from MG2a was employed in Northern-blot analysis. This probe specifically hybridized to two mRNA species from human submandibular and sublingual glands. A cDNA clone selected from a human submandibular gland cDNA expression library with antibody generated against deglycosylated MG2a also hybridized to these two mRNA species. In both cases, the larger mRNA was polydisperse, and the hybridization signal was more intense in the sublingual gland. In addition, the N-terminal amino acid sequence of the larger glycopeptide was found to be part of one of the selected MG2 cDNA clones.


1990 ◽  
Vol 265 (3) ◽  
pp. 789-798 ◽  
Author(s):  
P M Darrah ◽  
S A Kay ◽  
G R Teakle ◽  
W T Griffiths

Putative protochlorophyllide reductase cDNA clones (252 and 113) were isolated from an etiolated-oat (Avena sativa) cDNA library. These were used to indirectly characterize a further clone, p127, isolated from a lambda-phage gt11 cDNA library. The latter (1.15 kb in length) was sequenced, and the derived amino acid sequence was shown to be remarkably similar to that derived from chemical analysis of a CNBr-cleavage fragment of the purified reductase, p127 codes for more than 95% of the reductase protein.


1990 ◽  
Vol 126 (1) ◽  
pp. 141-149 ◽  
Author(s):  
W. C. Warren ◽  
R. Liang ◽  
G. G. Krivi ◽  
N. R. Siegel ◽  
R. V. Anthony

ABSTRACT Discrepancies exist in the reported purity and biological activity of ovine placental lactogen (oPL), and little structural characterization has been reported. Ovine PL was purified from fetal cotyledonary tissue (day 100 of gestation) by monitoring activity with a recombinant bovine GH (bGH) liver radioreceptor assay. Two hundred grams of tissue yielded 4·2 mg of oPL, with an ∼ 1000-fold purification of oPL specific activity following initial tissue extraction. The oPL was radioiodinated and used in an ovine fetal liver (day 100 of gestation) radioreceptor assay to examine competitive displacement of oPL, ovine GH (oGH) and ovine prolactin (oPRL). The potency of oPL (ED50 = 0·18 nmol/l; ED50 is the quantity of ligand necessary to displace 50% of specifically bound 125I-labelled oPL) was greater than that of oGH (ED50 = 4·1 nmol/l) and oPRL (ED50 = 1·1 μmol/l) in competing for 125I-labelled oPL-binding sites. Attempts to sequence the NH2 terminus of oPL by vapour-phase sequencing indicated that the NH2 terminus was blocked. Purified oPL was subjected to trypsin and CnBr digestion, and two CnBr and six tryptic peptides were sequenced. The peptide sequences were compared with other PLs, oPRL and bGH for sequence similarity, and found to be most similar to bovine PL (bPL; 68% overall identity) and oPRL (47% overall identity). Complementary DNA (cDNA) clones were isolated for oPL by screening a λZAP cDNA library with a cDNA coding for bPL. Three cDNAs were nucleotide sequenced, and their combined sequence included 41 nucleotides of 5'-untranslated region, the complete coding region of pre-oPL (708 nucleotides) and a portion of the 3' untranslated region (158 nucleotides). The predicted amino acid sequence derived from the nucleotide sequence confirmed homology to bPL (67%) and oPRL (48%). Little amino acid sequence existed with other PLs (≤29%) or GH proteins (≤27%). These results suggest that oPL and oGH are more biologically similar in their ability to compete for fetal liver binding sites, but that oPL is structurally more similar to oPRL. Elucidation of exact structure–function relationships for oPL will, however, require further investigation. Journal of Endocrinology (1990) 126, 141–149


1990 ◽  
Vol 111 (4) ◽  
pp. 1593-1604 ◽  
Author(s):  
R N Tamura ◽  
C Rozzo ◽  
L Starr ◽  
J Chambers ◽  
L F Reichardt ◽  
...  

The integrin alpha 6 beta 4 is a heterodimer predominantly expressed by epithelia. While no definite receptor function has yet been assigned to it, this integrin may mediate adhesive and/or migratory functions of epithelial cells. We have determined the complete primary structure of both the alpha 6 and beta 4 subunits from cDNA clones isolated from pancreatic carcinoma cell line libraries. The deduced amino acid sequence of alpha 6 is homologous to other integrin alpha chains (18-26% identity). Antibodies to an alpha 6 carboxy terminus peptide immunoprecipitated alpha 6 beta 4 complexes from carcinoma cells and alpha 6 beta 1 complexes from platelets, providing further evidence for the association of alpha 6 with more than one beta subunit. The deduced amino acid sequence of beta 4 predicts an extracellular portion homologous to other integrin beta chains, and a unique cytoplasmic domain comprised of greater than 1,000 residues. This agrees with the structures of the beta 4 cDNAs from normal epithelial cells (Suzuki, S., and Y. Naitoh. 1990. EMBO [Eur. Mol. Biol. Organ.] J. 9:757-763; Hogervost, F., I. Kuikman, A. E. G. Kr. von dem Borne, and A. Sonnenberg. 1990. EMBO [Eur. Mol. Biol. Organ.] J. 9:765-770). Compared to these structures, however, the beta 4 cDNAs that we have cloned from carcinoma cells contain extra sequences. One of these is located in the 5'-untranslated region, and may encode regulatory sequences. Another specifies a segment of 70 amino acids in the cytoplasmic tail. Amplification by reverse transcription-polymerase chain reaction of mRNA indicated that multiple forms of beta 4 may exist, possibly due to cell-type specific alternative splicing. The unique structure of beta 4 suggests its involvement in novel cytoskeletal interactions. Consistent with this possibility, alpha 6 beta 4 is mostly concentrated on the basal surface of epithelial cells, but does not colocalize with components of adhesion plaques.


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