726
|
Yin Y, Rogers PV, Rutherford CL. Dual regulation of the glycogen phosphorylase 2 gene Dictyostelium discoideum: the effects of DIF-1, cAMP, NH3 and adenosine. Development 1994; 120:1169-78. [PMID: 8026327 DOI: 10.1242/dev.120.5.1169] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cell differentiation in Dictyostelium results in the formation of two cell types, stalk and spore cells. The stalk cells undergo programmed cell death, whereas spore cells retain viability. The current evidence suggests that stalk cell differentiation is induced by Differentiation Inducing Factor (DIF), while spore cell differentiation occurs in response to cAMP. We have discovered the first developmentally regulated Dictyostelium gene, the glycogen phosphorylase gene 2 (gp2) gene, that can be induced by both DIF-1 and cAMP, suggesting the possibility of a new group of developmentally regulated genes that have DIF-1 and cAMP dual responsiveness. The gp2 gene was found to be expressed in both prestalk/stalk cells and prespore/spore cells. The DIF-1 competence of the gp2 gene required uninterrupted development, whereas the cAMP-competence for the gene required only starvation. Both DIF-1 and cAMP induction of the gene could be inhibited by NH3, a factor that is thought to act as a developmental signal in Dictyostelium. Another developmental signal, adenosine, was found to repress the DIF-1 induction of the gp2 gene. Two introns in the gp2 gene were examined for their involvement in the regulation of the gene, but no regulatory function was detected. A model for the regulation of the gp2 gene during the development is proposed.
Collapse
|
727
|
Rogers PV, Sucic JF, Yin Y, Rutherford CL. Disruption of glycogen phosphorylase gene expression in Dictyostelium: evidence for altered glycogen metabolism and developmental coregulation of the gene products. Differentiation 1994; 56:1-12. [PMID: 8026640 DOI: 10.1046/j.1432-0436.1994.56120001.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Glycogen phosphorylase 1 and 2, the isozymes responsible for glycogen degradation, are encoded by separate genes in Dictyostelium. The two gene products display different transcriptional and translational expression and distinct post-translational regulation. Using DNA-mediated transformation, Dictyostelium clones which lacked either glycogen phosphorylase 1 or 2 (gp1 or gp2) expression were obtained. The loss of either enzyme did not change axenic growth patterns, developmental progression, or gross organismic morphology. In gp1- strains, glycogen accumulated to a 17- to 28-fold higher level during late stationary phase without any obvious detrimental effects. This implies that no alternative pathway for glycogen degradation is present in amoebae, and that glycogen metabolism is not critical for vegetative cell growth. Developmental glycogen concentrations were not altered significantly in any of the transformants, but in gp2- cells the posttranslational regulation of the intact gp1 enzyme was apparently modulated to compensate for the loss of gp2. Western blots of microdissected, lyophilized Dictyostelium slugs and early culminates showed that gp2 was found in both prestalk and prespore cells, with a slight enrichment in prespore cells. The gp1 protein was highly enriched in prestalk cells in the parental strain. In gp2- transformants, however, gp1 was detected in equal amounts in both cell types. The loss of gp2 led to a shift in the cell-type-specific expression pattern of gp1, presumably due to developmental coordinate regulation of gp1 and gp2 at the translational and/or transcriptional level.
Collapse
|
728
|
Yin Y, Gilula LA. A 30-year-old woman with 13-year history of pain in multiple joints. ORTHOPAEDIC REVIEW 1994; 23:266-8, 272. [PMID: 8022649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first two pages. The final clinical and roentgenographic differential diagnoses are presented on the following pages.
Collapse
|
729
|
Yin Y, Rotman MB, Gilula LA. A 73-year-old woman with stiffness in both hands. ORTHOPAEDIC REVIEW 1994; 23:171-5. [PMID: 8196977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.
Collapse
|
730
|
Barrett JC, Annab LA, Alcorta D, Preston G, Vojta P, Yin Y. Cellular senescence and cancer. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1994; 59:411-8. [PMID: 7587095 DOI: 10.1101/sqb.1994.059.01.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
731
|
Wang Y, Yin Y, Gilula LA, Wilson AJ. Endemic fluorosis of the skeleton: radiographic features in 127 patients. AJR Am J Roentgenol 1994; 162:93-8. [PMID: 8273699 DOI: 10.2214/ajr.162.1.8273699] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE A wide range of radiographic appearances have been reported in skeletal fluorosis, but little has been written about the spectrum of radiographic features. We evaluated the spectrum of radiographic appearances in this disorder to help with its diagnosis and differentiation from other metabolic skeletal disorders. MATERIALS AND METHODS One hundred twenty-seven patients with clinically proved endemic fluorosis had radiographs of the chest, spine, pelvis, elbow, forearm, and knee obtained. The radiographic findings were classified as osteosclerosis, osteopenia, intermittent growth lines, diaphyseal widening, or soft-tissue ossification. Two different osteopenic patterns were defined: an osteoporotic pattern with overall decreased bone density and an osteomalacic pattern that combines the features of osteoporosis with bone deformity. Soft-tissue ossification included involvement of ligaments, tendons, and interosseous membranes. RESULTS Ninety-eight of the patients (89% of the adults) had some evidence of calcification and/or ossification of the attachments of ligaments, tendons, muscles, and interosseous membranes. Osteosclerosis was seen in 54 patients (43%), and osteopenia was seen in 51 patients (40%). Of the patients with osteopenia, the osteoporotic pattern was seen in 28 and the osteomalacic pattern in 23. Growth lines were found in 89 patients (70%). Metaphyseal osteomalacic zones were found in children. Diaphyseal widening was present in 35 patients (28%). CONCLUSION Endemic skeletal fluorosis can have a wide variety of radiographic appearances, including calcification and/or ossification of the attachments of soft-tissue structures to bone, osteosclerosis, osteopenia, growth lines, and metaphyseal osteomalacic zones.
Collapse
|
732
|
Sucic JF, Luo S, Williamson BD, Yin Y, Rogers PV, Rutherford CL. Developmental and cAMP-mediated regulation of glycogen phosphorylase 1 in Dictyostelium discoideum. JOURNAL OF GENERAL MICROBIOLOGY 1993; 139:3043-52. [PMID: 8126431 DOI: 10.1099/00221287-139-12-3043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The Dictyostelium discoideum glycogen phosphorylase-1 (gp-1) exhibits a complex pattern of developmental expression in which differential temporal regulation of enzyme activity, protein levels and mRNA levels is observed. This pattern of expression implies that gp-1 regulation occurs at multiple levels, probably involving both transcriptional and post-transcriptional events. Post-translational control of gp-1 activity, in effect, actually regulates the protein from a developmental perspective. In this report we have examined several facets of this regulation. We show that addition of exogenous cAMP to cells in suspension culture caused changes in gp-1 enzyme activity and mRNA levels that are identical to those observed during normal development, suggesting that cAMP is involved in the regulation of gp-1. Exogenous cAMP could regulate gp-1 mRNA expression at concentrations as low as 1.0 microM. cAMP regulation of gp-1 mRNA appeared to occur through a mechanism that required intracellular cAMP signalling. We identified regions of the promoter necessary for gp-1 expression by using gp-1 promoter deletions to drive the expression of a luciferase reporter gene. Results of these experiments suggested that developmental and cAMP-mediated changes in gp-1 mRNA levels were the result of alterations in transcription. The promoter analysis also suggested that a vegetative specific element is located between -785 and -1894 nucleotides from the transcriptional start site. Elements necessary for maximal developmental and cAMP-mediated expression appear to be located between -1153 and -1894 nucleotides from the cap site. Sequence elements located between -180 and -1153 appear to be required for a basal level of late developmental expression.
Collapse
MESH Headings
- Animals
- Base Sequence
- Cyclic AMP/metabolism
- Cyclic AMP/pharmacology
- DNA, Fungal/genetics
- DNA, Protozoan/genetics
- Dictyostelium/genetics
- Dictyostelium/growth & development
- Dictyostelium/metabolism
- Gene Expression Regulation, Fungal
- Genes, Fungal
- Genes, Protozoan
- Genes, Reporter
- Luciferases/genetics
- Molecular Sequence Data
- Phosphorylases/genetics
- Phosphorylases/metabolism
- Promoter Regions, Genetic
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Protozoan/genetics
- RNA, Protozoan/metabolism
Collapse
|
733
|
Bruce WR, Archer MC, Corpet DE, Medline A, Minkin S, Stamp D, Yin Y, Zhang XM. Diet, aberrant crypt foci and colorectal cancer. Mutat Res 1993; 290:111-8. [PMID: 7694090 DOI: 10.1016/0027-5107(93)90038-h] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have used the aberrant crypt focus (ACF) assay to test and develop hypotheses linking diet and colon cancer. The hypotheses were suggested by epidemiological studies that identified possible dietary factors associated with colorectal cancer risk. The ACF assay was used to quantitate the effect of the dietary factors on the initiation and growth of these putative precursors of colon cancers in experimental animals. Using this approach we have developed 3 new hypotheses for the role of diet in colorectal cancer. These are (1) a risk associated with 5-hydroxymethyl-2-furaldehyde in caramelized sugar, (2) a risk associated with some factor in thermolyzed casein, and (3) a risk associated with single nutrient boluses of sucrose and fructose. The importance of these hypotheses has still to be tested in long term carcinogenesis experiments, in analytic epidemiology studies and then, perhaps, in intervention trials.
Collapse
|
734
|
Yin Y, Rotman MB, Gilula LA. A 21-year-old man with pain and swelling of the right hand. ORTHOPAEDIC REVIEW 1993; 22:1051-7. [PMID: 8247622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on this page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.
Collapse
|
735
|
Yin Y, Gilula L. A 43-year-old woman with right hip pain. ORTHOPAEDIC REVIEW 1993; 22:943-9. [PMID: 8265233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Although tuberculous arthritis is currently uncommon in the United States, the hip joint is a common location. Tuberculous arthritis usually presents as a mild, slowly progressing process. It often involves a single joint. Radiological findings include osteopenia of the involved joint, soft tissue swelling, bone destruction without evidence of bone formation, and sequestrum formation. Several conditions should be considered in the differential diagnosis. The detailed roentgenographic appearances and many of the differential diagnoses are included in this paper. Final diagnosis is made by positive culture results or finding the bacillus histologically.
Collapse
|
736
|
Suzuki Y, Yin Y, Makino M, Kurimura T, Wakamiya N. S12.5 Cloning and sequencing of a cDNA coding for bovine conglutinin. Glycoconj J 1993. [DOI: 10.1007/bf01210039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
737
|
Prasad SM, Yin Y, Rodzinski E, Tuomanen EI, Masure HR. Identification of a carbohydrate recognition domain in filamentous hemagglutinin from Bordetella pertussis. Infect Immun 1993; 61:2780-5. [PMID: 8514379 PMCID: PMC280921 DOI: 10.1128/iai.61.7.2780-2785.1993] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The adherence of Bordetella pertussis to ciliated cells and macrophages is critical to colonization and infection of the respiratory tract. Adherence to both types of cells involves the recognition of eukaryotic carbohydrates by the bacterial adhesin filamentous hemagglutinin (Fha). The carbohydrate recognition domain (CRD) of Fha is considered an important antigen for subcomponent vaccines to maximize the generation of antiadherence antibodies capable of protecting against colonization. For identification of the CRD of Fha, a bank of eight monoclonal antibodies (MAbs) that mapped to four contiguous regions were tested for their ability to block Fha binding to lactosylceramide or to block bacterial binding to ciliated cells. Only MAb 12.5A9, which maps to amino acid residues 1141 to 1279, blocked both Fha binding to lactosylceramide and bacterial binding to ciliated cells. An 18-kDa polypeptide corresponding to this region was expressed in Escherichia coli. Cell lysates containing this protein bound to lactosylceramide in a manner identical to that of native Fha. Mutant strains of B. pertussis that contained an in-frame deletion of the coding sequence for this region produced a truncated Fha that showed negligible cross-reactivity with MAb 12.5A9. In an adherence assay, these mutant strains failed to bind efficiently to either ciliated cells or macrophages. The numbers of adherent bacteria for these strains were reduced to the number obtained with a nonadherent strain. We conclude that the region defined by residues 1141 to 1279 of Fha constitutes a CRD critical for bacterial adherence and represents a potential candidate for a subcomponent vaccine.
Collapse
|
738
|
Yin Y, Gilula LA. A 77-year-old man with a gradually enlarging mass of the left ring finger. ORTHOPAEDIC REVIEW 1993; 22:865-8. [PMID: 8414664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.
Collapse
|
739
|
Yin Y, Yunzhao W, Gilula LA. A 54-year-old woman with a 15-year history of pain in both legs and back. ORTHOPAEDIC REVIEW 1993; 22:735-41. [PMID: 8351178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
740
|
Zhou HM, Zhang XH, Yin Y, Tsou CL. Conformational changes at the active site of creatine kinase at low concentrations of guanidinium chloride. Biochem J 1993; 291 ( Pt 1):103-7. [PMID: 8471027 PMCID: PMC1132487 DOI: 10.1042/bj2910103] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
It has been previously reported that, during denaturation of creatine kinase by guanidinium chloride (GdmCl) or urea [Tsou (1986), Trends Biochem. Sci. 11, 427-429], inactivation occurs before noticeable conformational change can be detected, and it is suggested that the conformation at the active site is more easily perturbed and hence more flexible than the molecule as a whole. In this study, the thiol and amino groups at or near the active site of creatine kinase are labelled with o-phthalaldehyde to form a fluorescent probe. Both the emission intensity and anisotropy decrease during denaturation indicating exposure of this probe and increased mobility of the active site. The above conformational changes take place together with enzyme inactivation at lower GdmCl concentrations than required to bring about intrinsic fluorescence changes of the enzyme. At the same GdmCl concentration, the rate of exposure of the probe is comparable with that of inactivation and is several orders of magnitude faster than that for the unfolding of the molecule as a whole.
Collapse
|
741
|
Yin Y, Gilula LA. A 35-year-old-man with pain in the metatarsophalangeal joints. Soft-tissue chondroma. ORTHOPAEDIC REVIEW 1993; 22:483-6, 488. [PMID: 8479794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on the first two pages. The final clinical and roentgenographic differential diagnoses are presented on the following pages.
Collapse
|
742
|
Suzuki Y, Yin Y, Makino M, Kurimura T, Wakamiya N. Cloning and sequencing of a cDNA coding for bovine conglutinin. Biochem Biophys Res Commun 1993; 191:335-42. [PMID: 8460993 DOI: 10.1006/bbrc.1993.1222] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A 912 bp bovine cDNA fragment encoding bovine conglutinin was amplified by the RT-PCR technique. cDNA clones encoding the bovine conglutinin were isolated from a bovine liver cDNA library using a specific probe obtained from the PCR product. These cDNAs carry an insert of 1113 bp coding for a protein of 371 amino acid residues with a signal peptide of 20 residues. The deduced amino acid sequence of cDNA agrees with that determined by conventional amino acid sequence analysis. Two polyadenylation signal sequences were detected in the DNA sequence downstream of the 3' end of the gene. Southern blot analysis of total bovine genomic DNA indicated that there is only one copy of the gene encoding bovine conglutinin. Northern blot analysis of bovine tissues showed that conglutinin mRNA of about 1.5 kb is expressed in the liver and also slightly in the lung.
Collapse
|
743
|
Yin Y, Gilula LA. A 67-year-old woman with pain and tenderness in the left long finger. ORTHOPAEDIC REVIEW 1993; 22:381-2, 387. [PMID: 8474777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are presented along with the final histologic and differential diagnoses.
Collapse
|
744
|
Yin Y, Riordan M, Gilula LA. A 2-year-old girl with painful right ankle. ORTHOPAEDIC REVIEW 1993; 22:243-9. [PMID: 8451076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The following case is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. The initial history, physical findings, and roentgenographic examinations are found on this page. The final clinical and roentgenographic differential diagnosis is then presented.
Collapse
|
745
|
Di Leonardo A, Linke SP, Yin Y, Wahl GM. Cell cycle regulation of gene amplification. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1993; 58:655-67. [PMID: 7956082 DOI: 10.1101/sqb.1993.058.01.073] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
746
|
Boerrigter ME, Yin Y, Vijg J, Wei JY. DNA repair in congenic mice: possible influence of a chromosome 4 genetic region on the rate of benzo[a]pyrene-induced DNA adduct removal. JOURNAL OF GERONTOLOGY 1993; 48:B11-6. [PMID: 8418133 DOI: 10.1093/geronj/48.1.b11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An attempt was made to assign mouse lifespan-associated interstrain differences in DNA repair to a specific chromosomal region using a set of congenic mice. The sensitive 32P-postlabeling assay was employed to measure the removal of benzo[a]pyrene-induced DNA adducts in liver DNA of three different chromosome 4 congenic mouse strains: B6.C-H-15c, B6.C-H-16c, and B6.C-H-26c and the two parental strains, C57B1/6 and BALB/c. The removal of the one main adduct detected, trans-(7R)-N2-[10-(7 beta,8 alpha,9 alpha-trihydroxy)-7,8,9,10- tetrahydrobenzo(a)-pyrene]-yl-deoxyguanosine (BPDE-N2-dG), in liver DNA of C57Bl/6 and BALB/c mice between one and three days after treatment, was approximately 86% and 57%, respectively. The percentage removal of BPDE-N2-dG in two of the three congenic mouse strains, B6.C-H-16c and B6.C-H-26c, resembled that found in BALB/c, whereas the third strain, B6.C-H-15c, removed about the same amount as C57B1/6, i.e., approximately 88% of BPDE-N2-dG between one and three days after treatment. The usefulness of congenic mouse strains for identifying genes putatively involved in aging and/or disease susceptibility is discussed.
Collapse
|
747
|
Yin Y, Wang Y, Gilula LA, Tian G. A 35-year-old man with right wrist pain. ORTHOPAEDIC REVIEW 1992; 21:1253-7, 1260. [PMID: 1437253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The following is presented to illustrate the roentgenographic and clinical findings of a condition of interest to the orthopaedic surgeon. The initial history, physical findings, and roentgenographic examinations are found on this page. The final clinical and roentgenographic differential diagnoses are presented on the following pages.
Collapse
|
748
|
Yin Y, Tainsky MA, Bischoff FZ, Strong LC, Wahl GM. Wild-type p53 restores cell cycle control and inhibits gene amplification in cells with mutant p53 alleles. Cell 1992; 70:937-48. [PMID: 1525830 DOI: 10.1016/0092-8674(92)90244-7] [Citation(s) in RCA: 854] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Loss of cell cycle control and acquisition of chromosomal rearrangements such as gene amplification often occur during tumor progression, suggesting that they may be correlated. We show here that the wild-type p53 allele is lost when fibroblasts from patients with the Li-Fraumeni syndrome (LFS) are passaged in vitro. Normal and LFS cells containing wild-type p53 arrested in G1 when challenged with the uridine biosynthesis inhibitor PALA and did not undergo PALA-selected gene amplification. The converse occurred in cells lacking wild-type p53 expression. Expression of wild-type p53 in transformants of immortal and tumor cells containing mutant p53 alleles restored G1 control and reduced the frequency of gene amplification to undetectable levels. These studies reveal that p53 contributes to a metabolically regulated G1 check-point, and they provide a model for understanding how abnormal cell cycle progression leads to the genetic rearrangements involved in tumor progression.
Collapse
|
749
|
Yin Y, McEnery KW, Gilula LA, Krain S. An 80-year-old man with symptoms of bilateral carpal tunnel syndrome. ORTHOPAEDIC REVIEW 1992; 21:1109-12, 1117. [PMID: 1437261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
750
|
Abstract
Dgp1, a circular 4.4-kb plasmid found in the nuclei of Dictyostelium giganteum strain DG61, is a member of the same plasmid family as plasmids Ddp2 and pDG1. Dgp1 has sequence similarity to a conserved region of the Ddp2 and pDG1 open reading frames. As with Ddp2 and pDG1, a single large RNA is transcribed from Dgp1. This 3.3-kb transcript is present at about 350 copies per vegetative cell. The transcript abundance decreased about 10-fold in early aggregation and continued at this lower level until late culmination when it returned to the level seen in vegetative cells. Dgp1 has a repeat of several hundred base pairs in a location, relative to the transcribed region, similar to the inverted repeats found in Ddp2 and pDG1. Dgp1 cannot be maintained as a plasmid in Dictyostelium discoideum AX4 cells, suggesting that Dgp1 carries species-specific maintenance elements.
Collapse
|