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J Battey

Publications and source records attributed to J Battey.

At least 37 records · Page 2Linked to original sources
PubMed1992

The human gene for oxytocin-neurophysin I (OXT) is physically mapped to chromosome 20p13 by in situ hybridization.

Two posterior pituitary hormones oxytocin and arginine-vasopressin control the important activities of water excretion, parturition and lactation. Both these hormones are synthesized as inactive precursors in the hypothalamus along with their carrier proteins neurophysin I and neurophysin II respectively and are activated upon transport to posterior pituitary. Human genes for both oxytocin-neurophysin I (OXT) and arginine-vasopressin-neurophysin II (ARVP) are cloned and found to be linked on chromosome 20 separated by approximately 12 kb of intergenic sequences. Though OXT is not yet associated with any disease, ARVP is linked to the autosomal dominant disease neurohypophyseal diabetes insipidus (AD-NDI). We have mapped regionally the OXT locus to chromosome 20p13 by both radioactive (ISH) and fluorescence in situ hybridization (FISH).

Arginine Vasopressin↗
PubMed1992

Molecular genetic analysis of two distinct receptors for mammalian bombesin-like peptides.

The mammalian bombesin-like peptides are known to be growth factors for certain cells with high-affinity bombesin receptors and have been implicated as autocrine growth factors influencing the pathogenesis and progression of a subset of human small-cell lung carcinomas. Thus, antagonists that interfere with bombesin receptor-ligand interaction might prove to be of value in treatment of gastrin-releasing peptide (GRP)-responsive tumors. A precise definition of the structure and properties of the bombesin receptors found on human lung cancer cells would provide important information for the design and rational application of such antagonists. Recently, we isolated cDNA clones encoding two distinct receptors for the mammalian bombesin-like peptides, GRP, and neuromedian B (NMB). The two receptors show 56% amino acid identity, encode seven putative transmembrane domains, and are members of the G-protein-coupled receptor superfamily. Ligand-binding studies show that while both receptors can be activated by either GRP or NMB, one receptor has a higher affinity for GRP than for NMB (GRP-R), while the other has a higher affinity for NMB than for GRP (NMB-R). A different spectrum of antagonists is needed to block responses from the two different receptors. These studies indicate that it will be critical in future studies to define which bombesin receptor subtypes are present on a given tumor to optimize the potential therapeutic benefit of antagonists in blocking growth.

Amino Acid Sequence↗
PubMed1991

Squid low molecular weight neurofilament proteins are a novel class of neurofilament protein. A nuclear lamin-like core and multiple distinct proteins formed by alternative RNA processing.

The primary structure of the major 60-kDa squid low molecular mass neurofilament protein (NF60) and a related 70-kDa neurofilament protein have been determined from cDNA clones isolated from a squid brain cDNA library. Structural analysis suggests that the squid NF60 and NF70 neurofilament genes and proteins are remarkably distinct from vertebrate neuronal intermediate filaments characterized previously. Both proteins are encoded on mRNAs generated by alternative RNA processing of the primary transcript of a single gene. Among the known intermediate filament proteins, NF60 and NF70 neurofilament proteins show highest similarity to an epithelial intermediate filament protein from Helix pomatia, a gastropod mollusk, and are less similar to vertebrate neurofilaments. The length of the alpha-helical rod domain in the NF60 and NF70 proteins was reminiscent of the vertebrate nuclear lamins, 6 heptads longer than is found in all known vertebrate cytoplasmic intermediate filaments, in particular the vertebrate neurofilaments. These distinct structural properties suggest that the vertebrate and invertebrate low molecular weight neurofilaments evolved independently from primordial intermediate filament proteins.

Amino Acid Sequence↗
PubMed1991

Two distinct receptor subtypes for mammalian bombesin-like peptides.

The mammalian bombesin-like peptides, gastrin-releasing peptide (GRP) and neuromedin B (NMB), are structurally related neuropeptides that elicit a wide spectrum of biological activities including regulation of smooth muscle contraction, stimulation of secretion, modulation of neural activity, and growth regulation. Earlier studies have shown that GRP and NMB are expressed in different regions of both the CNS and peripheral organs. Recent ligand-binding and molecular-cloning studies have revealed two pharmacologically distinct G-protein-coupled receptor subtypes for mammalian bombesin-like peptides that have different relative affinities for GRP, NMB and bombesin receptor antagonists. Similar to the peptide ligands, the two receptor subtypes are expressed in a distinct but overlapping set of CNS regions, some of which have been identified in functional studies as sites where bombesin peptides elicit defined biological responses. Delineation of these peptide ligands and receptor subtypes will be important in future studies that explore the molecular basis for the heterogeneous nature of the responses to bombesin observed in mammalian systems.

Amino Acid Sequence↗
PubMed1990

Application for PCR technology to subtractive cDNA cloning: identification of genes expressed specifically in murine plasmacytoma cells.

We describe a simple method for preparing a renewable source of subtractive cDNA which can be used as a hybridization probe or as insert which can be cloned into a variety of convenient vectors. This has been done by ligating a double-stranded oligonucleotide to each end of double-stranded subtractive cDNA, and then using this oligonucleotide sequence to amplify the heterogeneous population of cDNA molecules using the polymerase chain reaction and thermostable Taq DNA polymerase. This method improves the chances for identifying cDNA clones representing low abundance mRNAs that are expressed differentially. Using this approach, we have identified cDNA clones which detect three different low abundance mRNAs that are expressed in mouse plasmacytoma cell lines but not in mouse pre-B or B lymphoma cell lines.

Animals↗
PubMed1990

Structural characterization of a brain-specific promoter region directing transcription of the rat prepro-gastrin-releasing peptide gene.

Expression of the mammalian prepro-gastrin-releasing peptide (preproGRP) gene has been shown to be restricted to neural and neuroendocrine cell types. In this paper, the structure and nucleotide sequence of the rat preproGRP gene coding regions and promoter is described and analyzed. The gene is divided into 3 exons, encoding a signal sequence, the 29 amino acid rat GRP, and a 92 amino acid extension peptide. While the overall prohormone structure is similar to that predicted from the sequence of the human gene, differences in transcription are apparent. Several forms of the rat preproGRP mRNA are found in brain: a 1.1 kb form which initiates in both brain and gut primarily from a TATAA-directed promoter, and less abundant forms of about 1.5 kb, whose initiation sites are heterogeneous, located 300-400 base pairs upstream of the 1.1 kb initiation site, and found only in spinal cord and a subset of brain nuclei expressing preproGRP mRNA. Comparison of the human and rat promoter region sequences identifies regions of high similarity upstream from both the 1.1 kb and 1.5 kb mRNA initiation sites, which may be important in the cell type-specific regulation of the preproGRP gene.

Amino Acid Sequence↗
PubMed1990

Structure of mouse vasopressin and oxytocin genes.

Mouse vasopressin (VP) and oxytocin (OT) genes were isolated from a genomic library and the nucleotide sequences of the two genes were determined. The two genes have similar three exon structures and a high similarity in the part of exon 1 encoding vasopressin or oxytocin nonapeptide and in exon 2 encoding the central core of neurophysin. They are linked together in a tail to tail orientation separated by a short 3.5 kb intergenic sequence and are transcribed from opposite strands. Both genes have a single transcription initiation site downstream from a TATA-like sequence and a single polyadenylated transcript of about 760 bp for the vasopressin mRNA and about 700 bp for the oxytocin mRNA.

Amino Acid Sequence↗
PubMed1990

Molecular analysis of autosomal dominant neurohypophyseal diabetes insipidus.

The status of the arginine vasopressin-neurophysin-II (AVP-NPII) gene was studied in three families with autosomal dominant neurohypophyseal diabetes insipidus (AD-NDI). Restriction fragments of genomic DNA containing AVP-NPII sequences from affected individuals were not detectably different in size from those of normal controls. Thus, these individuals with ADNDI do not have apparent large deletions, insertions, or rearrangements of an AVP-NPII allele. Four restriction fragment length polymorphisms were detected with a probe for the adjacent gene on chromosome 20, oxytocin-neurophysin-I (OT-NPI). Linkage studies in these three families between the restriction fragment length polymorphism haplotypes and ADNDI phenotype strongly suggest cosegregation. This indicates that the genetic locus for ADNDI maps within or near the AVP-NPII locus and suggests that a defective AVP-NPII allele may be the basis of ADNDI.

Arginine Vasopressin↗
PubMed1990

Linkage relationships of human arginine vasopressin-neurophysin-II and oxytocin-neurophysin-I to prodynorphin and other loci on chromosome 20.

The structural genes for human prepro-arginine-vasopressin-neurophysin II (prepro-AVP-NPII; ARVP) locus and prepro-oxytocin-neurophysin-I (prepro-OT-NPI; OT) locus are closely linked separated by only 12 kilobasepairs of DNA. These two loci have been assigned to chromosome 20 by previous studies of somatic cell hybrids. We used Southern blots to analyze a restriction fragment length polymorphism detected by a probe for prepro-OT-NPI to determine the linkage relationships for the ARVP/OT loci using samples from the Centre d'Etude du Polymorphisme Humain (Paris, France) collection of families. The ARVP/OT loci demonstrated extremely close linkage with the prodynorphin (PDYN) locus, with no recombinants (theta of 0) and a log10 odds score of 5.2. Previous observations have shown the ARVP and PDYN peptides to be coexcreted in the same neurosecretory granules of some pituitary axons and that increased transcription of both genes occurs with osmotic stimulation. The combined ARVP/PT/PDYN group was also found to demonstrate linkage with other anonymous DNA segments on chromosome 20, including D20S4, D20S5, and D20S6. Using multilocus linkage analysis, the ARVP/OT loci map to the distal short arm of chromosome 20 about 15 centimorgans toward the telomere from the D20S5 locus, which is located near the middle of the short arm at 20p 12.21. These linkage relationships establish that the secretory and transcriptional associations of ARVP and PDYN extend to a close physical relationship in the human genome. Furthermore, the restriction fragment length polymorphism detected by these loci can serve as accurate markers in segregation studies of putative defects involving the OT, ARVP, or PDYN loci as well as provide a tool for studying the location of other genes, such as GH-releasing hormone.

Arginine Vasopressin↗
PubMed1988

Structure and expression of the human L-myc gene reveal a complex pattern of alternative mRNA processing.

We analyzed in detail the structure of the L-myc gene isolated from human placental DNA and characterized its expression in several small-cell lung cancer cell lines. The gene is composed of three exons and two introns spanning 6.6 kilobases in human DNA. Several distinct mRNA species are produced in all small-cell lung cancer cell lines that express L-myc. These transcripts are generated from a single gene by alternative splicing of introns 1 and 2 and by use of alternative polyadenylation signals. In some mRNAs there is a long open reading frame with a predicted translated protein of 364 residues. Amino acid sequence comparison with c-myc and N-myc demonstrated multiple discrete regions with extensive homology. In contrast, other mRNA transcripts, generated by alternative processing, could encode a truncated protein with a novel carboxy-terminal end.

Amino Acid Sequence↗
PubMed1988

The human L-myc gene encodes multiple nuclear phosphoproteins from alternatively processed mRNAs.

The human proto-oncogene L-myc generates at least four different mRNAs by alternative RNA processing. We have identified two phosphorylated L-myc proteins with molecular masses of 60,000 and 66,000 daltons [p60L-myc(human) and p66L-myc(human)] in a small-cell carcinoma line expressing high levels of L-myc mRNA. These proteins have a short half-life and are localized to the nuclear matrix fraction, as previously reported for the c-myc and N-myc proteins. In vitro translation experiments demonstrated that both the p60 and p66 species are encoded by a 3.9-kilobase (kb) mRNA which retains intron 1, while only the p60 protein is translated from a 3.6-kb L-myc mRNA which has had intron 1 removed. While L-myc proteins [p32L-myc(human) and p37L-myc(human)] could be synthesized in vitro from 2.2-kb mRNA templates, no such proteins were detected by immunoprecipitation in vivo. These observations suggest that alternative RNA processing of the L-myc transcript could play a role in determining the steady-state levels of the p60L-myc and p66L-myc proteins.

Humans↗
PubMed1988

Multiple mechanisms for transcriptional regulation of the myc gene family in small-cell lung cancer.

The molecular mechanisms reported to regulate the expression of myc family genes are multiple and complex and include gene amplification, transcriptional activation, transcriptional attenuation, and mRNA stability. We have investigated which of these mechanisms are responsible for the extreme variation in myc gene family mRNA levels observed in human small-cell lung cancer cell lines. In addition to gene amplification, a block to nascent mRNA chain elongation, causing attenuation of transcription, is an important regulatory mechanism controlling the steady-state levels of c-myc and L-myc mRNA. The loss of transcriptional attenuation is correlated with overexpression of these two genes in cell lines which do not show gene amplification. Expression of c-myc mRNA appears to be dependent on promoter activity and attenuator function. In contrast, regulation of expression of the N-myc gene does not involve transcriptional attenuation; steady-state mRNA levels are correlated with promoter activity as well as gene amplification. We conclude that transcriptional regulation of each member of the myc gene family is accomplished by a different assortment of complex mechanisms, including gene copy number, promoter activation, and transcriptional attenuation. Interference at multiple points in this complex regulatory process appears to be an important mechanism by which small-cell lung cancer and other human tumors evade growth control.

Carcinoma, Small Cell↗
PubMed1988

Transcriptional activation and DNase I hypersensitive sites are associated with selective expression of the gastrin-releasing peptide gene.

The gastrin-releasing peptide (GRP) is a neuropeptide hormone and growth factor produced normally by neural and neuroendocrine cells, as well as by human small-cell lung cancer (SCLC) tumors and derived cell lines. This study compares the structure of the human prepro-GRP gene in four SCLC cell lines that express variable levels of steady-state GRP mRNA. The regulation of GRP gene expression appears to be at the level of primary transcription based on nuclear run on studies. In the two SCLC cell lines expressing GRP we find a single transcription start site for GRP mRNA, and near this site we find four DNase I hypersensitive sites. These hypersensitive sites are absent in the two cell lines that do not express GRP. The presence of DNase hypersensitive sites in the promoter region of the GRP gene is the structural feature that best correlates with transcriptional activation. These four DNase hypersensitive sites are candidates for cis acting regulatory regions, which may be important in determining the level of transcription of the human prepro GRP gene.

Base Sequence↗
PubMed1987

Human gastrin-releasing peptide gene maps to chromosome band 18q21.

A complementary DNA clone encoding human pre-pro gastrin-releasing peptide, a 27-amino acid neuropeptide and putative growth factor, was used to determine the chromosomal location of this gene. Southern blot hybridization to genomic DNA isolated from a panel of human-rodent somatic cell hybrids unambiguously maps this gene to human chromosome 18. In situ chromosomal hybridization confirms the hybrid data and further localized the gene to chromosome band 18q21. Karyotypic abnormalities in tumors and inherited disease states which involve chromosome band 18q21 may now be studied for correlated changes in the structure and expression of the human GRP gene.

Animals↗
PubMed1986

A translocated human c-myc oncogene is altered in a conserved coding sequence.

We have cloned and characterized a c-myc (now designated MYC) oncogene that had been translocated into the mu switch region of the immunoglobulin heavy chain locus in a Burkitt lymphoma cell line. The breakpoint of the translocation occurs within the first intron of the c-myc gene, thereby separating the untranslocated first exon from the two coding exons. Transcription from the translocated gene arises from a cryptic promoter within the first intron, which produces a 438-nucleotide untranslated 5' region. The amino acid sequence of the protein encoded by the c-myc gene has been substantially altered. In particular, a compensating set of frameshift mutations alters a string of 24 amino acids in a region of the protein tightly conserved in human, mouse, and chicken c-myc genes as well as in the human N-myc and L-myc oncogenes. Despite this, the mutated gene retains a reduced transforming ability in a rat embryo fibroblast focus-formation assay.

Amino Acid Sequence↗
PubMed1986

Changes in the phenotype of human small cell lung cancer cell lines after transfection and expression of the c-myc proto-oncogene.

Small cell lung cancer growing in cell culture possesses biologic properties that allow classification into two categories: classic and variant. Compared with classic small cell lung cancer cell lines, variant lines have altered large cell morphology, shorter doubling times, higher cloning efficiencies in soft agarose, and very low levels of L dopa decarboxylase production and bombesin-like immunoreactivity. C-myc is amplified and expressed in some small cell lung cancer cell lines and all c-myc amplified lines studied to date display the variant phenotype. To investigate if c-myc amplification and expression is responsible for the variant phenotype, a normal human c-myc gene was transfected into a cloned classic small cell lung cancer cell line not amplified for or expressing detectable c-myc messenger RNA (mRNA). Clones were isolated with one to six copies of c-myc stably integrated into DNA that expressed c-myc mRNA. In addition, one clone with an integrated neo gene but a deleted c-myc gene was isolated and in this case c-myc was not expressed. C-myc expression in transfected clones was associated with altered large cell morphology, a shorter doubling time, and increased cloning efficiency, but no difference in L dopa decarboxylase levels and bombesin-like immunoreactivity. We conclude increased c-myc expression observed here in transfected clones correlates with some of the phenotypic properties distinguishing c-myc amplified variants from unamplified classic small cell lung cancer lines.

Animals↗
PubMed1986

Comparison of amplified and unamplified c-myc gene structure and expression in human small cell lung carcinoma cell lines.

A human small cell lung cancer cell line (H82) demonstrates 40- to 50-fold amplification of the c-myc gene but expresses at least 250-fold more steady-state c-myc messenger RNA than an unamplified small cell lung cancer cell line (H378) with no detectable expression of c-myc. We compared the chromatin structure of c-myc in H82 to that in H378 using DNase I sensitivity and DNA methylation patterns. DNase I hypersensitivity sites were identical in H82 and H378 and were similar to the pattern seen in a B-lymphoblastoid cell line, despite extensive amplification of c-myc in H82. Methylation patterns were also very similar in H82 and H378, with hypomethylation or partial methylation at the c-myc coding regions and the flanking 5' sequences, despite the absence of detectable c-myc expression in H378. Therefore, the predominant chromatin structural patterns do not appear to correlate with observed differences in gene expression. In addition, these studies demonstrate that the patterns of DNase I hypersensitivity and of methylation can remain intact during a 40- 50-fold gene amplification, as observed for the c-myc gene in H82.

Carcinoma, Small Cell↗