PubMed Health⌕ Search

Biomedical subjects

V J Kidd

Publications and source records attributed to V J Kidd.

At least 73 records · Page 4Linked to original sources

Polymorphism and expression of the galactosyltransferase-associated protein kinase gene in normal individuals and galactosylation-defective rheumatoid arthritis patients.

We used restriction endonuclease digestion of leukocyte DNA to assess the structural integrity of an N-acetylglucosamine beta 1----4 galactosyltransferase (GalTase)-associated (GTA) protein kinase gene in rheumatoid arthritis (RA) patients. This analysis provides evidence that the gross structure of the GTA protein kinase gene locus remains intact in patients with defective galactosylation and that this gene locus is polymorphic both in normal individuals and in patients with RA, although no polymorphisms unique to RA patients were observed. Initial data on the expression of this gene indicate that comparable levels of GTA protein kinase messenger RNA are present in the lymphocytes of normal individuals and RA patients, irrespective of whether lymphocytes were obtained from patients with decreased or normal levels of galactosylation.

Acetylglucosamine↗

A dominant negative mutation in two proteins created by ectopic expression of an AU-rich 3' untranslated region.

We have found that the ectopic expression of a specific gene's 3' untranslated region leads to the dose dependent loss, relative to gene copy number, of that specific mRNA and protein, as well as an associated protein, in a eukaryotic cell line. The loss of these proteins from the eukaryotic cell line also results in specific phenotypic changes in these cells, suggesting that we have created a dominant negative mutant. This gene's 3' untranslated region is known to contain numerous AU sequences, reminiscent of other eukaryotic genes whose expression may be regulated by these sequences. The apparent control of gene expression by a truncated 3' untranslated region sequence provides further evidence supporting the regulatory function of these regions. The resulting decrease in steady-state mRNA levels by the overexpression of a portion of that gene's 3' untranslated region further suggests the possible existence of a factor(s) that may bind to this region, and thus regulate gene function via its mRNA. The use of a gene's 3' untranslated sequence to create a specific dominant negative mutation may also be applicable to other eukaryotic genes whose expression is controlled by similar regulatory sequences.

Adenine↗

Increased expression of a 58-kDa protein kinase leads to changes in the CHO cell cycle.

We have isolated and characterized cDNA encoding a human 58-kDa protein kinase that is homologous to the cell division control (CDC) protein kinases. This protein kinase also contains a unique N-terminal domain that may potentially regulate its function. Due to its relatedness to p34CDC2, the human p58 cDNA was overexpressed in CHO cells to determine the effect on the cell cycle. Elevated expression of p58 in these cells resulted in prolonged late telophase and early G1 phase of the cell cycle. These p58 overexpressors showed a significantly increased frequency of tubulin midbodies as well as significant increases in mitotic abnormalities. Thus, proper regulation of p58 protein kinase is essential for normal cell cycle progression in these cells.

Amino Acid Sequence↗

cDNA cloning and expression of human complement component C2.

A full-length cDNA clone for C component C2 was isolated from a human liver cDNA library in lambda gt11 by initially screening with an affinity-purified rabbit anti-C2 antibody and then using the isolated partial C2 cDNA as a probe for re-screening the library. The cDNA insert of clone lambda C2HL5-3 was sequenced in its entirety. It consisted of 2961 nucleotides including a 5' untranslated region of 388 nucleotides, followed by a 60 nucleotide region coding for a putative signal peptide, a 2196 nucleotide region coding for the 732 amino acids of the mature C2 polypeptide, and a 317 nucleotide long 3' untranslated region. Comparison of the nucleotide sequence to the previously reported C2 cDNA sequence showed two major differences. First, the 5' untranslated region of C2HL5-3 was 352 nucleotides longer and included four ATG followed by in-frame termination codons. Second, nucleotide residue 1987 was a C instead of a G, resulting in a change of amino acid residue 513 from Leu to Phe and in the appearance of an EcoRI site. The full-length C2 cDNA was cloned into the expression vector p91023(B). Transfection of the recombinant plasmid in COS cells resulted in the secretion of a protein with antigenicity and hemolytic activity similar to those of native C2. Western blot analysis indicated that secreted rC2 had the same apparent m.w. as C2 in human serum. Northern blot analysis of total RNA isolated from transfected COS cells showed two bands of C2 mRNA, both of which were longer than human liver C2 mRNA and represent transcripts generated by the vector-C2 construct.

Amino Acid Sequence↗

In vitro and in vivo growth control of transformed lymphoid cells expressing plasma membrane galactosyltransferase.

The level of beta 1-4 galactosyltransferase activity was examined in a number of spontaneously, chemically, or virally transformed murine tumor cell lines. Increased levels of enzyme activity were observed for the murine myeloma cell line K181 and in vivo MOPC 104E. The Maloney Sarcoma Virus (MSV) transformed T-cell lymphoma, YC-8, also demonstrated elevated levels of enzyme activity when compared to a second independently MSV transformed T stem-cell lymphoma, LSTRA. Cell surface immunofluorescence was also detected in YC-8 with a monoclonal antibody for galactosyltransferase. The introduction of galactosyltransferase specific substrates, both in vivo and in vitro, led to the retardation of growth in the cell lines K181, MOPC 104E, and YC-8, but not in the cell line LSTRA; this suggests the selective growth control of transformed cells demonstrating elevated levels of galactosyltransferase.

Animals↗

A frameshift mutation results in a truncated alpha 1-antitrypsin that is retained within the rough endoplasmic reticulum.

The major physiological role of the serine protease inhibitor alpha 1-antitrypsin (alpha 1-AT) is to protect elastic fibers in the lung from excessive hydrolysis by neutrophil elastase. Genetic deficiency of alpha 1-AT predisposes individuals toward the development of emphysema. We have cloned and characterized a mutant alpha 1-AT gene from an individual exhibiting a total absence of immunoreactive alpha 1-AT in serum. Nucleotide sequence analysis of this "null" allele has demonstrated a TC dinucleotide deletion within the codon for Leu318 in exon IV. This frame-shift mutation results in the generation of a premature termination codon at residue 334, which is upstream of the active inhibitory site. To determine the biochemical basis of the null phenotype, the mutant and normal genes were transferred into mouse hepatoma cells for expression analysis. Pulse-chase experiments demonstrated that the mutant gene is expressed into a truncated protein of 45 kDa, which is retained within the rough endoplasmic reticulum. The complete lack of secretion of the truncated protein is consistent with the absence of immunoreactive alpha 1-AT in the patient's serum. In addition, a G to A transition was identified in exon II of the mutant gene, changing the codon for Arg101 to His101. Finally, an A to C transversion was identified in exon V changing the codon for Glu376 to Asp376. Since the latter conservative amino acid substitution has previously been identified in the common PiM2 variant, the frame-shift mutation might have occurred on a PiM2 background chromosome. Using the birthplace of this index case, this mutant alpha 1-AT allele has been designated "nullHong Kong."

Alleles↗

Cell surface expression of 4 beta-galactosyltransferase accompanies rat parotid gland acinar cell transition to growth.

Rat parotid gland acinar cells stimulated to divide by a chronic regimen of isoproterenol demonstrate a dramatic increase in the synthesis of the glycosyltransferase 4 beta-galactosyltransferase. A plasma membrane localization for much of the increase in 4 beta-galactosyltransferase was determined by density gradient membrane fractionation. Golgi-enriched fractions showed no increase in specific activity, while plasma membrane activity increased 40-fold. This selective increase at the cell surface was confirmed by immunofluorescence of intact, nonpermeabilized cells from treated glands, using a monospecific antibody prepared against the purified bovine milk transferase. In detergent-permeabilized cells staining of nontreated cells was seen only as groups of perinuclear vesicles, presumed to be Golgi apparatus. In isoproterenol-treated and permeabilized cells both presumptive Golgi and cell surface staining was apparent. Enzyme assays performed on intact cells established that the enzyme's active site was oriented to the exterior of the cells. The transferase could be detected as early as 3 hr after the primary challenge with isoproterenol. Pretreatment of rats with cycloheximide prevented its appearance.

Animals↗

Molecular structure and sequence homology of a gene related to alpha 1-antitrypsin in the human genome.

A 7.7-kb EcoRI genomic DNA fragment highly homologous to the human alpha 1-antitrypsin (AAT) gene has been cloned. This antitrypsin-related sequence is physically linked to the authentic AAT gene and both are present in a single cosmid clone. Nucleotide sequencing of the AAT-related genomic fragment demonstrated extensive homology with the authentic AAT gene in the introns as well as in the exons. The conservation of all RNA splice sites and lack of internal termination codons in the exonic regions suggest that it may not be a classical pseudogene. If expressed, it could result in a protein of 420 amino acid residues exhibiting a 70% overall homology with human alpha 1-antitrypsin. The signal peptide sequence is well conserved in the related gene, but the active site for protease inhibition of Met-Ser in alpha 1-antitrypsin has been changed to Trp-Ser. These data suggest that the putative protein encoded by the AAT-related gene is a secretory serine protease inhibitor with an altered substrate specificity. Interestingly, even the intronic regions in the related gene exhibit a 65% overall nucleotide sequence homology with those of the authentic AAT gene. These results suggest that the AAT-related gene is derived from a recent duplication of the authentic AAT gene and represents a new member of the serine protease inhibitor superfamily.

Amino Acid Sequence↗

Molecular evolution of serpins: homologous structure of the human alpha 1-antichymotrypsin and alpha 1-antitrypsin genes.

alpha 1-Antichymotrypsin belongs to a supergene family that includes alpha 1-antitrypsin, antithrombin III, ovalbumin, and angiotensinogen. The human chromosomal alpha 1-antichymotrypsin gene has been cloned and its molecular structure established. The gene is approximately 12 kb in length and contains five exons and four introns. The locations of the introns within the alpha 1-antichymotrypsin gene are identical with those of the human alpha 1-antitrypsin and angiotensinogen genes. Other members of this supergene family contain introns located at nonhomologous positions of the genes. The homologous organization of the alpha 1-antichymotrypsin and alpha 1-antitrypsin genes corresponds with the high degree of homology between their protein sequences and suggests that these loci arose by recent gene duplication. A model is presented for the evolution of both the genomic structure and the protein sequences of the serine protease inhibitor superfamily.

Animals↗

Isoproterenol-mediated parotid gland hypertrophy is inhibited by effectors of 4 beta-galactosyltransferase.

Chronic administration of the beta-adrenergic receptor agonist isoproterenol results in parotid gland hypertrophy and hyperplasia. This physiological change in the gland has recently been reported to be accompanied by a dramatic increase in the rate of synthesis and accumulation of the enzyme 4 beta-galactosyltransferase. Here, isoproterenol-induced hypertrophy of the parotid gland is shown to be blocked by the introduction of the 4 beta-galactosyltransferase modifier protein alpha-lactalbumin and also by specific antiserum to bovine 4 beta-galactosyltransferase. Partial inhibition of gland enlargement was observed stereospecifically with UDP-galactose and with the competitive acceptor glycoprotein, ovalbumin, as well. These agents did not affect the induction by isoproterenol of the biosynthesis of the proline-rich proteins nor of 4 beta-galactosyltransferase. These agents also inhibited the incorporation of thymidine by isoproterenol-stimulated parotid cells in culture.

Animals↗

Molecular cloning, cDNA structure, and regulation of the regulatory subunit of type II cAMP-dependent protein kinase from rat ovarian granulosa cells.

One isoform of the regulatory subunit of type II cAMP-dependent protein kinase (R-II51; Mr = 51,000) and its electrophoretic variants (R-II51.5 and R-II52; Mr = 51,500 and 52,000, respectively) are selectively induced by estradiol and follicle-stimulating hormone (cAMP) in rat ovarian granulosa cells. To ascertain the amino acid sequence of R-II51 and to gain insight into the molecular events regulating the intracellular content of ovarian follicular R-II51, we constructed a lambda gt11 cDNA expression library from poly(A)+ RNA of hormone-primed rat granulosa cells. A 1.5-kilobase (kb) cDNA insert, isolated from a plaque-purified R-II antibody positive bacteriophage clone, selectively bound R-II51 mRNA as demonstrated by analysis of the hybrid-selected translation product. Restriction maps and sequence analyses of the 1.5-kb cDNA insert and of the 1.8- and 2.2-kb cDNA inserts from two additional clones showed overlapping sequences which span a region of 3065 nucleotides in size. The 1.5- and 1.8-kb cDNA inserts each contained poly(A) addition signals (1508 and 1761 nucleotides, respectively), terminal poly(A) sequences, and the entire coding region for R-II51 (1204 nucleotides) except for a small number of nucleotides at the 5' end. The 2.2-kb cDNA insert contained 394 nucleotides of the coding region a long 3' untranslated region and two more poly(A) addition signals (3041 and 3059 nucleotides). An amino acid microsequence surrounding the autophosphorylation site of pure rat ovarian R-II51 agreed with the amino acid sequence deduced from the nucleotide sequence of the cDNA. Northern blot analyses demonstrated two major mRNA species (1.8 and 3.2 kb in size) in hormone-primed rat ovaries which were approximately 10- and 50-fold greater than the R-II mRNA content in rat brain and rat heart, respectively. Southern blot analysis of rat liver DNA indicated that a single gene codes for R-II51 mRNA. Structural differences among rat ovarian R-II51, rat heart R-II54, and the known amino acid sequences of bovine R-II and R-I subunits also indicate that the rat ovarian R-II51 subunit is the product of a distinct gene.

Amino Acid Sequence↗

Molecular cloning and chromosomal localization of human 4-beta-galactosyltransferase.

A cDNA clone to human 4-beta-galactosyltransferase (EC 2.4.1.38) was isolated from a human liver lambda gt11 expression library by using a monospecific polyclonal antiserum to affinity-purified bovine enzyme. The authenticity of this cDNA clone has been demonstrated by several criteria. Under conditions of chronic treatment with the beta-adrenergic receptor agonist isoproterenol, rat parotid glands show an approximately 10-fold increase in 4-beta-galactosyltransferase activity. The increased enzyme activity was reflected in dot-blot analysis of control and isoproterenol-treated rat parotid RNA by using the human cDNA as probe. Hybrid-selection and in vitro translation identified a protein product with a molecular mass of 47 kDa that was immunoprecipitated with the bovine antiserum. The full-length human cDNA clone was then isolated and the DNA sequence for the NH2-terminal portion of the protein was deduced. Comparison of the NH2-terminal protein sequence from the bovine protein with that of the human cDNA clone confirmed its identity. In addition, the human cDNA clone was used to localize the gene for 4-beta-galactosyltransferase to human chromosome 4 by Southern analysis of a somatic cell hybrid panel.

Amino Acid Sequence↗

Complete absence of serum alpha-1-antitrypsin in conjunction with an apparently normal gene structure.

A family in which a Pinull allele for alpha-1-antitrypsin (A-1-AT) segregates has been studied in detail. Two homozygous sisters have no detectable A-1-AT in their serum as measured with the most sensitive methods currently available. Both have airways obstruction, and one has bullous emphysema. Heterozygotes for Pinull and the common normal allele PiM1 have half-normal serum concentrations of A-1-AT. A restriction enzyme analysis of chromosomal DNA of the two homozygotes and one heterozygote demonstrated the presence of an apparently complete structural gene for A-1-AT. Thus, the genetic defect in Pinull is not a complete or partial deletion of the structural gene. A base pair change that cannot be detected by the restriction enzymes used here, of course, cannot be excluded. Another possibility is a mutation outside the structural gene that affects the synthesis of the protein.

Adult↗

Sequence homology between human alpha 1-antichymotrypsin, alpha 1-antitrypsin, and antithrombin III.

alpha 1-Antichymotrypsin mRNA was isolated by specific polysome immunoprecipitation from turpentine-treated baboon liver. The highly enriched mRNA was used for synthesis and cloning of the corresponding cDNA. Baboon alpha 1-antichymotrypsin cDNA clones were identified by hybrid-selected translation, and the insert DNA fragment from one of the putative clones was used as a probe to screen a human liver cDNA library comprised of 40 000 independent transformants. One of the human cDNA clones was unambiguously identified to contain alpha 1-antichymotrypsin DNA sequences by comparison of its 5'-terminal nucleotide sequence with the N-terminal amino acid sequence of the protein. This cDNA clone, designated phACT235, contains 1524 base pairs of human DNA, which was sequenced in its entirety. The inserted DNA codes for a 25 amino acid signal peptide sequence and the entire mature alpha 1-antichymotrypsin of 408 amino acid residues. Comparison of the amino acid sequence of alpha 1-antichymotrypsin with that of the human alpha 1-antitrypsin has revealed a homology level similar to that between chymotrypsin and trypsin.

Amino Acid Sequence↗

Isolation and sequence characterization of a cDNA clone of human antithrombin III.

A human liver cDNA library was constructed by using poly(A)-containing RNA isolated from a human liver biopsy specimen. This library is comprised of 40,000 independent transformants with an average inserted DNA length of 1,200 base pairs. By using the previously cloned baboon antithrombin III cDNA as a specific hybridization probe, greater than 30 human antithrombin III cDNA clones were identified from this library. The clone with the longest DNA insert was selected for sequence analysis. This antithrombin III cDNA clone contains 1,479 base pairs of inserted human DNA and was designated phATIII 113. It contains DNA sequences that code for a signal peptide and the entire mature antithrombin III protein which is comprised of 432 amino acid residues.

Amino Acid Sequence↗

Linkage arrangement of human placental lactogen and growth hormone genes.

Human placental lactogen (hPL) and growth hormone (hGH) are two hormones thought to have evolved from a common ancestral gene (along with prolactin), yet they have quite different functions and specificities. The nucleic acid sequences of the respective cDNAs of the two genes share considerable homology, as well as the existence of multiple forms of each gene within the genome. In this study we report on the linkage arrangement of several genes from this group. Two hPL-like genes as well as an hGH gene are shown to be linked within a 38-kilobase pair region of DNA. Linkage between a variant hGH gene and an hPL gene is also shown. The orientation and structural organization of these genes was previously established using 5'- and 3'-specific probes from a placental lactogen cDNA clone and detailed restriction endonuclease mapping. Restriction fragments from the overlapping clones were verified by comparison to digests of high molecular weight genomic DNA. In addition, the location of a specific class of repetitive DNA sequences, the Alu family, was mapped on these clones using the recombinant clone BLUR 8. All members of this multigene family have Alu repeat sequences either immediately flanking their 3' or 5' untranslated regions or within their intervening sequences.

Base Sequence↗