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V J Kidd

Publications and source records attributed to V J Kidd.

At least 37 records · Page 2Linked to original sources
PubMed1998

Duplication of the DR3 gene on human chromosome 1p36 and its deletion in human neuroblastoma.

The human DR3 gene, whose product is also known as Wsl-1/APO-3/TRAMP/LARD, encodes a tumor necrosis factor-related receptor that is expressed primarily on the surface of thymocytes and lymphocytes. DR3 is capable of inducing both NF-kappa B activation and apoptosis when overexpressed in mammalian cells, although its ligand has not yet been identified. We report here that the DR3 gene locus is tandemly duplicated on human chromosome band 1p36.2-p36.3 and that these genes are hemizygously deleted and/or translocated to another chromosome in neuroblastoma (NB) cell lines with amplified MYCN. Duplication of at least a portion of the DR3 gene, including the extracellular and transmembrane regions but not the cytoplasmic domain, was demonstrated by both fluorescence in situ hybridization and genomic Southern blotting. In most NB cell lines, both the DR3 and the DR3L sequences are simultaneously deleted and/or translocated to another chromosome. Finally, DR3/ Wsl-1 protein expression is quite variable among these NB cell lines, with very low or undetectable levels in 7 of 17 NB cell lines.

Animals↗
PubMed1998

Fluorescence in situ hybridization analysis of chromosome 1p36 deletions in human MYCN amplified neuroblastoma.

BACKGROUND/PURPOSE: Deletion of the short arm of chromosome 1 (1p) is one of the poor prognostic factors in human neuroblastomas. Recent studies have suggested that one or more of the neuroblastoma tumor suppressor genes reside in this region and have identified the shortest region of overlap (SRO) on 1p36. The purpose of this study was to examine deletions of 1p in human neuroblastomas by fluorescence in situ hybridization (FISH). METHODS: Two-color FISH analysis was performed to detect chromosome 1p36 abnormalities in 42 MYCN-amplified neuroblastomas. Four different probes from the 1p36 region, the E2F2, NPPA, D1S160, and CDC2L1 loci were used for detection of 1p abnormalities. A repeat sequence probe, which is specific for the heterochromatic region of chromosome 1 (pUC1.77), was used as a control. RESULTS: Large deletions of 1p36 were observed in 31 (73.8%) of 42 tumors, whereas the remaining 11 (26.2%) showed no deletion. In these 11 tumors, a translocation of 1p was found in one and a duplication of 1p was detected in another. CONCLUSIONS: A strong correlation between 1p abnormalities and MYCN amplification was found in this study. MYCN-amplified neuroblastomas were found to show large deletions of 1p encompassing the SRO. FISH provided a rapid and reliable method to detect hemizygous deletions of 1p.

Child, Preschool↗
PubMed1998

Duplication of a genomic region containing the Cdc2L1-2 and MMP21-22 genes on human chromosome 1p36.3 and their linkage to D1Z2.

Cdc2L1 and Cdc2L2 span approximately 140 kb on human chromosome 1p36.3. The products of the Cdc2L genes encode almost identical protein kinases, the PITSLRE kinases, which have functions that may be relevant to the regulation of transcription/splicing and apoptotic signaling. These genes are deleted/translocated in neuroblastomas with MYCN gene amplification, a subset of malignant melanomas, and in a newly delineated deletion syndrome. Here we report that the p36.3 region of human chromosome 1 consists of two identical genomic regions, each of which contain a Cdc2L gene linked to a metalloprotease (MMP) gene in a tail-to-tail configuration. This duplicated genomic region is also linked tightly to D1Z2, a genetic marker containing a highly polymorphic VNTR (variable number tandem repeat) consisting of an unusual 40-bp reiterated sequence. Thus, these genes and the polymorphic marker D1Z2 are organized as follows: telomere-D1Z2-5'-MMP22-3'-3'-Cdc2L2-5'-5'-Cdc2L1 -3'- 3'-MMP21-5'-centromere. Remarkably, the introns and exons of Cdc2L1 and Cdc2L2, as well as their flanking regions, are essentially identical. A total of 15 amino acid differences, 12 nonconservative and 3 conservative, can be found in the 773-786 amino acids specified by the various products of the Cdc2L genes. Two separate promoter/5' untranslated (UT) regions, CpG1 and CpG2, are identical to a reported previously methylated genomic CpG sequence and are used to express >20 different Cdc2L transcripts from the two genes. The expression of CpG2 transcripts from Cdc2L1 and Cdc2L2 is tissue/cell-line specific. CpG1 transcripts are expressed ubiquitously from both genes, with perhaps some bias towards the expression of CpG1 Cdc2L1 mRNAs in certain hematopoietic cells.

5' Untranslated Regions↗
PubMed1998

Proteolytic activities that mediate apoptosis.

Since the discovery that cells can activate their own suicide program, investigators have attempted to determine whether the events that are associated with this form of cell death are genetically determined. The discovery that the ced-3 gene of Caenorhabditis elegans encodes a cysteine protease essential for developmentally regulated apoptosis ignited interest in this area of research. As a result, we now know that cell death is specified by a number of genes and that this biologic process contributes significantly to development, tumorigenesis, and autoimmune disease. In this review I summarize what is currently known about signaling pathways involved in apoptosis, with particular emphasis on the function of the cysteine proteases known as caspases. However, there is also evidence that protease-independent cell death pathways exist. Is there a relationship between these two distinct mechanisms? If so, how do they communicate? Finally, even though the involvement of tumor necrosis factor/nerve growth factor family of receptors and cysteine proteases has been elegantly established as a component of many apoptotic signaling pathways, what happens downstream of these initial events? Why are only a selected group of cellular proteins--many nuclear--the targets of these proteases? Are nuclear events essential for apoptosis in vivo? Are the cellular genes that encode products involved in apoptotic signaling frequent targets of mutation/alteration during tumorigenesis? These are only a few questions that may be answered in the next ten years.

Animals↗
PubMed1998

The RNP protein, RNPS1, associates with specific isoforms of the p34cdc2-related PITSLRE protein kinase in vivo.

The PITSLRE protein kinases are members of the p34cdc2 superfamily, with >20 different isoforms expressed from two linked genes in humans. PITSLRE homologues have been identified in mouse, chicken, Drosophila, Xenopus, and possibly Plasmodium falciparum, suggesting that their function may be well conserved. A possible role for a caspase processed PITSLRE isoform has been suggested by studies of Fas- and TNF-induced cell death. However, the function of these kinases in proliferating cells is still unknown. Here we demonstrate that the 110 kDa PITSLRE isoforms (p110) are localized to both the nucleoplasm and nuclear speckles, and that these isoforms specifically interact in vitro and in vivo with the RNA-binding protein RNPS1. RNPS1 is also localized to nuclear speckles, and its over expression disrupts normal nuclear speckle organization by causing the aggregation of many nuclear speckles into approximately 6 'mega' speckles. This type of nuclear speckle aggregation closely resembles what occurs when cells are treated with several transcriptional inhibitors. These data indicate that the PITSLRE p110 isoforms interact with RNPS1 in vivo, and that these proteins may in turn influence some aspect of transcriptional and/or splicing regulation.

Animals↗
PubMed1997

Cleavage of PITSLRE kinases by ICE/CASP-1 and CPP32/CASP-3 during apoptosis induced by tumor necrosis factor.

Emerging evidence suggests that multiple aspartate-specific cysteine proteases (caspases (CASPs)) play a crucial role in programmed cell death. Many cellular proteins have been identified as their substrates and serve as markers to assay the activation of CASPs during the death process. However, no substrate has yet been unambiguously identified as an effector molecule in apoptosis. PITSLRE kinases are a superfamily of Cdc2-like kinases that have been implicated in apoptotic signaling and tumorigenesis. In this paper we report that tumor necrosis factor (TNF)-mediated apoptosis is associated with a CrmA- and Bcl-2-inhibitable cleavage of PITSLRE kinases, indicating a role for CASPs. Testing of seven murine CASPs for their ability to cleave p110 PITSLRE kinase alpha2-1 in vitro revealed that only CASP-1 (ICE (interleukin-1beta-converting enzyme)) and CASP-3 (CPP32) were able to produce the same 43-kDa cleavage product as observed in cells undergoing TNF-induced apoptosis. Mutational analysis revealed that cleavage of p110 PITSLRE kinase alpha2-1 occurred at Asp393 within the sequence YVPDS, which is similar to that involved in the CASP-1-mediated cleavage of prointerleukin-1beta. TNF-induced proteolysis of PITSLRE kinases was still observed in fibroblasts from CASP-1(0/0) mice. These data implicate CASP-3 as a potentially important CASP family protease responsible for the cleavage of PITSLRE kinases during TNF-induced apoptosis.

Animals↗
PubMed1997

Elimination of cyclin D1 in vertebrate cells leads to an altered cell cycle phenotype, which is rescued by overexpression of murine cyclins D1, D2, or D3 but not by a mutant cyclin D1.

DT40 lymphoma B-cells normally express cyclins D1 and D2 but not D3. When cyclin D1 expression was extinguished in these cells by gene knockout, specific alterations in their ability to transit the cell cycle were observed. These changes are exemplified by a delay of approximately 2 h in their progression through a normal 14-h cell cycle. This delay results in an increase in the number of cells in the G2/M phase population, most likely due to triggering of checkpoints in G2/M, inability to enter G1 normally, and/or alterations of crucial event(s) in early G1. The defect(s) in the cell cycle of these D1 "knockout" cells can be rescued by overexpression of any normal mouse D-type cyclin but not by a mutant mouse cyclin D1 protein that lacks the LXCXE motif at its amino terminus. These data suggest that the cell cycle alterations observed in the D1-/- cells are a direct effect of the absence of the cyclin D1 protein and support the hypothesis that the D-type cyclins have separate, but overlapping, functions. Elimination of cyclin D1 also resulted in enhanced sensitivity to radiation, resulting in a significant increase in apoptotic cells. Expression of any normal murine D-type cyclin in the D1-/- cells reversed this phenotype. Intriguingly, expression of the mutant cyclin D1 in the D1 -/- cells partially restored resistance to radiation-induced apoptosis. Thus, there may be distinct differences in cyclin D1 complexes and/or its target(s) in proliferating and apoptotic DT40 lymphoma B-cells.

Amino Acid Sequence↗
PubMed1997

Characterization of putative human homologues of the yeast chromosome transmission fidelity gene, CHL1.

Helicases are components of numerous protein complexes, including those regulating transcription, translation, DNA replication and repair, splicing, and mitotic chromosome transmission. Helicases unwind double-stranded DNA and RNA homo- and hetero-duplexes. The yeast CHL1 helicase has been linked to maintenance of the high fidelity of chromosome transmission during mitosis. Mutations in this gene result in a 200-fold increase in the rate of aberrant chromosome segregation with a concomitant delay in the cell cycle at G2-M, suggesting that CHL1 is required for the maintenance of proper chromosome transmission. Two highly related human cDNA clones encoding proteins which are homologous to the yeast CHL1 gene product have been isolated. Here we show that these two distinct human CHL1-related mRNAs and proteins (hCHLR1 and hCHLR2) are expressed only in proliferating human cell lines. Quiescent normal human fibroblasts stimulated to re-enter the cell cycle by addition of serum begin to express the CHL1-related proteins as the cells enter S phase, concomitant with the expression of proliferating cell nuclear antigen. Furthermore, expression of the CHL1-related mRNAs is lost when human K562 cells cease to proliferate and terminally differentiate in response to phorbol ester treatments. Human hCHLR expression is not extinguished during hemin-induced differentiation of the same cell line, which produces erythrocyte-like cells that continue to proliferate. These experiments are consistent with the requirement of this putative helicase during either S or G2-M phase but not G1. In vitro transcribed and translated hCHLR1 protein binds to both single- and double-stranded DNA, supporting the possibility that these proteins are DNA helicases. Finally, affinity-purified hCHLR1 antisera was used to demonstrate the localization of the hCHLR proteins to the nucleolus by indirect immunofluorescence as well as by cell fractionation.

Amino Acid Sequence↗
PubMed1997

Fas activates NF-kappaB and induces apoptosis in T-cell lines by signaling pathways distinct from those induced by TNF-alpha.

The p55 tumor necrosis factor (TNF) receptor and the Fas (CD95/APO-1) receptor share an intracellular domain necessary to induce apoptosis, suggesting they utilize common signaling pathways. To define pathways triggered by Fas and TNF-alpha we utilized human CEM-C7 T-cells. As expected, stimulation of either receptor induced apoptosis and TNF-alpha-induced signaling included the activation of NF-kappaB. Surprisingly, Fas-induced signaling also triggered the activation of NF-kappaB in T cells, yet the kinetics of NF-kappaB induction by Fas was markedly delayed. NF-kappaB activation by both pathways was persistent and due to the sequential degradation of IkappaB-alpha and IkappaB-beta. However, the kinetics of IkappaB degradation were different and there were differential effects of protease inhibitors and antioxidants on NF-kappaB activation. Signaling pathways leading to activation of apoptosis were similarly separable and were also independent of NF-kappaB activation. Thus, the Fas and TNF receptors utilize distinct signal transduction pathways in T-cells to induce NF-kappaB and apoptosis.

Journal Article↗
PubMed1996

Alternatively spliced cyclin C mRNA is widely expressed, cell cycle regulated, and encodes a truncated cyclin box.

The cyclin C protein has recently been shown to associate with a unique cyclin dependent protein kinase (cdk8) and it has been proposed that this complex may regulate RNA transcription during the cell cycle. In addition, the human cyclin C gene has been localized to human chromosome 6q21 and it was found to be frequently deleted in a subset of acute lymphoblastic leukemias (ALL's). Screening of an avian T-cell cDNA library resulted in the isolation of a cyclin C homologue as well as an abundant, yet distinct, cyclin C-related cDNA. The predicted open reading frame (ORF) of the cyclin C cDNA predicted a 283 amino acid protein that was > 99% identical to the human protein and 72% identical to the Drosophila melanogaster protein. However, the predicted ORF of the cyclin C-related cDNA predicted a much smaller 105 amino acid protein that was identical to cyclin C well into the cyclin-box region (amino acid residue 98), where it abruptly diverges and then terminates. Using PCR analysis of cDNA derived from a range of cell lines and tissues, alternative splicing of the avian cyclin C gene has been demonstrated. Furthermore, a smaller approximately 19 kDa protein that co-migrates with the in vitro transcribed and translated truncated cyclin C protein was detected in normal and virally-transformed avian cells with a cyclin C-specific antibody. Expression of alternatively spliced cyclin C mRNA and protein is regulated in a cell cycle-dependent manner reminiscent of cyclin B2. The function of this truncated cyclin C protein is not known, but its expression in avian cells suggest that this truncated cyclin C protein may participate as an early endogenously encoded cyclin C inhibitor.

Alternative Splicing↗
PubMed1996

Molecular cloning and chromosomal localization of the human cyclin C (CCNC) and cyclin E (CCNE) genes: deletion of the CCNC gene in human tumors.

The human Gi-phase cyclins are important regulators of cell cycle progression that interact with various cyclin-dependent kinases and facilitate entry into S-phase. We have confirmed the localization of the human cyclin C (CCNC) gene to chromosome 6q21 and of human cyclin E (CCNE) to 19q12. The CCNC gene structure was also determined, and we have shown that it is deleted in a subset of acute lymphoblastic leukemias, including a patient sample containing a t(2;6)(p21;q15), with no apparent cytogenetic deletion. Single-strand conformational polymorphism analysis of the remaining CCNC allele from patients with a deletion of one allele established that there were no further mutations within the exons or the flanking intronic sequences. These results suggest either that haploinsufficiency of the cyclin C protein is sufficient to promote tumorigenesis or that the important tumor suppressor gene is linked to the CCNC locus.

Chromosome Mapping↗
PubMed1996

Localization of chi1-related helicase genes to human chromosome regions 12p11 and 12p13: similarity between parts of these genes and conserved human telomeric-associated DNA.

The helicase enzymes are essential components of a number of multi-protein complexes, including those that regulate transcription, splicing, translation, and DNA repair. These enzymes assist in the unwinding of double-stranded DNA and RNA as an essential part of their function. The yeast Chl1 gene encodes a putative helicase that appears to be essential for normal chromosome transmission. Human cDNAs related to this yeast gene, hCHLR1 and hCHLR2, were recently isolated and shown to encode products that localize to the nucleus. Two corresponding genes have now been partially characterized and localized to human chromosome regions 12p11 and 12p13, indicating that this gene is contained within a duplicated region localized to 12p. In addition, a comparison of the hCHLR gene sequences with available databases indicates that a large portion of these genes, including exons encoding two functional domains of the carboxyl-terminal region of these proteins, has been duplicated as part of a larger human telomeric repeat sequence found on many human chromosomes. Our results suggest that duplication of a relatively large region of chromosome 12p containing this putative helicase gene has resulted in the creation of numerous pseudogenes as part of a subtelomeric repeat. The presence of these helicase pseudogenes, as well as pseudogenes for other genes such as the interleukin-9 receptor, within many subtelomeric regions support the possibility that the spread of this region is subject to exchange between different chromosomes and may have implications for elucidation of the mechanism of intra- and interchromosomal duplication events.

Base Sequence↗
PubMed1995

Structure and gene expression of avian cyclin D2.

Avian cyclin D2 (Cyl D2)-encoding cDNA clones were isolated from a chicken UG9 T-cell lambda gt10 library. Sequence analysis revealed a high degree of sequence conservation with both the mouse and human Cyl D2, and somewhat lower similarity with the mouse and human Cyl D1 and D3. The homology is highest between species in the Cyl-box domain which is well conserved among human, mouse and chicken. A single 6.0-kb CYL2 mRNA is produced in both avian B- and T-cells, as expected.

Amino Acid Sequence↗
PubMed1995

Molecular cloning, expression pattern, and chromosomal localization of human CDKN2D/INK4d, an inhibitor of cyclin D-dependent kinases.

Progression through the G1 phase of the cell cycle is dependent on the activity of holoenzymes formed between D-type cyclins and their catalytic partners, the cyclin-dependent kinases cdk4 and cdk6. p16INK4a, p15INK4b, and p18INK4c, a group of structurally related proteins, function as specific inhibitors of the cyclin D-dependent kinases and are likely to play physiologic roles as specific regulators of these kinases in vivo. A new member of the INK4 gene family, murine INK4d, has recently been identified. Here we report the isolation of human INK4d (gene symbol CDKN2D), which is 86% identical at the amino acid level to the murine clone and approximately 44% identical to each of the other human INK4 family members. The INK4d gene is ubiquitously expressed as a single 1.4-kb mRNA with the highest levels detected in thymus, spleen, peripheral blood leukocytes, fetal liver, brain, and testes. The abundance of INK4d mRNA oscillates in a cell-cycle-dependent manner with expression lowest at mid G1 and maximal during S phase. Using a P1-phage genomic clone of INK4d for fluorescence in situ hybridization analysis, the location of this gene was mapped to chromosome 19p13. No rearrangements or deletions of the INK4d gene were observed in Southern blot analysis of selected cases of pediatric acute lymphoblastic leukemia (ALL) containing a variant (1;19)(q23;p13) translocation that lacks rearrangement of either E2A or PBX1, or in ALL cases containing homozygous or hemizygous deletions of the related genes, INK4a and INK4b.

Amino Acid Sequence↗
PubMed1995

Structure and expression of chicken protein kinase PITSLRE-encoding genes.

The human PITSLRE protein kinases (PK), members of the p34cdc2 kinase family named according to the single amino acid (aa) code of an important (PSTAIRE) regulatory region [Meyerson et al., EMBO J. 11 (1992) 2909-2917], are candidate tumor suppressor gene(s) localized to human chromosome 1p36.2 and a syntenic region of mouse chromosome 4 [Lahti et al., Nature Genet. 7 (1994) 370-375; Mock et al., Mammal. Genome 5 (1994) 191-192]. At least ten isoforms of this PK family are expressed from three duplicated and tandemly linked genes in humans [Xiang et al., J. Biol. Chem. 269 (1994) 15786-15794]. We have now isolated two different species of PITSLRE PK cDNAs from chicken that encode identical polypeptides, but are clearly expressed from different genes, based on nucleotide (nt) differences. Isolation of one of the corresponding chicken PITSLRE PK genes confirms that only one of the two species of PITSLRE mRNA is expressed from this gene. Comparison of the predicted avian PITSLRE PK aa sequence to human and mouse sequences shows a high degree of sequence identity (> 91%). Like humans, the PITSLRE PK genes in chickens must be closely linked, based on fluorescent in situ hybridization (FISH) localization of these genes to a single chicken microchromosome. PITSLRE PK mRNAs are expressed in two avian B- and T-cell lines. These results suggest that the PITSLRE PK gene family has been well conserved evolutionarily, that the gene duplication observed in humans is not a recent event, and that expression of redundant PITSLRE mRNAs is observed in different vertebrate species.

Amino Acid Sequence↗
PubMed1995

The PITSLRE protein kinase family.

A family of p34Cdc2 related protein kinases, the PITSLRE kinases, is generated by alternative splicing and promoter utilization from three duplicated and tandemly linked genes on human chromosome 1p36.3, which is frequently deleted during the late stages of tumorigenesis. PITSLRE mRNA, protein, and enzyme activity are induced during Fas receptor- and glucocorticoid-mediated apoptosis of human T cells. Several PITSLRE isoforms are specific targets of proteolysis during apoptosis, generating an enzymatically active 50 kDa isoform. Inhibition of this protease activity blocks PITSLRE processing and enzyme activation, as well as apoptosis. Thus, PITSLRE kinases may be integral downstream components of apoptotic signal transduction pathway(s). Furthermore, PITSLRE genes, and their products, are physically altered in human neuroblastoma tumors, suggesting that they may be tumor suppressors.

Animals↗