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Han X, Xu S, Wang L, Bi Z, Wang D, Bu H, Da J, Liu Y, Tan W. Artificial DNA Framework Channel Modulates Antiapoptotic Behavior in Ischemia-Stressed Cells via Destabilizing Promoter G-Quadruplex. ACS NANO 2024; 18:6147-6161. [PMID: 38372229 DOI: 10.1021/acsnano.3c06563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Regulating folding/unfolding of gene promoter G-quadruplexes (G4s) is important for understanding the topological changes in genomic DNAs and the biological effects of such changes on important cellular events. Although many G4-stabilizing ligands have been screened out, effective G4-destabilizing ligands are extremely rare, posing a great challenge for illustrating how G4 destabilization affects gene function in living cells under stress, a long-standing question in neuroscience. Herein, we report a distinct methodology able to destabilize gene promoter G4s in ischemia-stressed neural cells by mitigating the ischemia-induced accumulation of intracellular K+ with an artificial membrane-spanning DNA framework channel (DFC). We also show that ischemia-triggered K+ influx is positively correlated to anomalous stabilization of promoter G4s and downregulation of Bcl-2, an antiapoptotic gene with neuroprotective effects against ischemic injury. Intriguingly, the DFC enables rapid transmembrane transport of excessive K+ mediated by the internal G4 filter, leading to the destabilization of endogenous promoter G4 in Bcl-2 and subsequent turnover of gene expression at both transcription and translation levels under ischemia. Consequently, this work enriches our understanding of the biological roles of endogenous G4s and may offer important clues to study the cellular behaviors in response to stress.
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Affiliation(s)
- Xiaoyan Han
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Shujuan Xu
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Linlin Wang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Zhengyan Bi
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Dan Wang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Huitong Bu
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Jun Da
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Yanlan Liu
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China
- The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China
- Institute of Molecular Medicine (IMM), Renji Hospital, Shanghai Jiao Tong University School of Medicine, and College of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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2
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Burns JR, Howorka S. Defined Bilayer Interactions of DNA Nanopores Revealed with a Nuclease-Based Nanoprobe Strategy. ACS NANO 2018; 12:3263-3271. [PMID: 29493216 DOI: 10.1021/acsnano.7b07835] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
DNA nanopores are a recent class of bilayer-puncturing nanodevices that can help advance biosensing, synthetic biology, and nanofluidics. Here, we create archetypal lipid-anchored DNA nanopores and characterize them with a nanoprobe-based approach to gain essential information about their interactions with bilayers. The strategy determines the molecular accessibility of DNA pores with a nuclease and can thus distinguish between the nanopores' membrane-adhering and membrane-spanning states. The analysis reveals, for example, that pores interact with bilayers in two steps whereby fast initial membrane tethering is followed by slower reorientation to the puncturing state. Tethering occurs for pores with one anchor, while puncturing requires multiple anchors. Both low and high-curvature membranes are good substrates for tethering, but efficient insertion proceeds only for high-curvature bilayers of the examined lipid composition. This is likely due to the localized lipid misalignments and the associated lower energetic barrier for pore permeation. Our study advances the fields of DNA nanotechnology and nanopores by overcoming the considerable experimental hurdle of efficient membrane insertion. It also provides mechanistic insights to aid the design of advanced nanopores, and offers a useful route to probe bilayer orientation of DNA nanostructures.
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Affiliation(s)
- Jonathan R Burns
- Department of Chemistry, Institute of Structural Molecular Biology , University College London , London WC1H 0AJ , United Kingdom
| | - Stefan Howorka
- Department of Chemistry, Institute of Structural Molecular Biology , University College London , London WC1H 0AJ , United Kingdom
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3
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Abstract
Reaction conditions for a variety of endonucleases are detailed in this unit along with discussions of potential applications. Enzymes covered include BAL 31 nuclease, S1 nuclease, mung bean nuclease, micrococcal nuclease, and DNase I. A general discussion regarding the use of endonucleases to generate nonspecific breaks in dsDNA is also provided. For a detailed discussion of the endonucleases more typically associated with DNA damage repair (e.g., Endo III, IV, V and VIII of E. coli and human APE1), see UNIT 3.9.
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4
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Larson D, Bradford-Wilcox J, Young LS, Sprague KU. A short 5' flanking region containing conserved sequences is required for silkworm alanine tRNA gene activity. Proc Natl Acad Sci U S A 2010; 80:3416-20. [PMID: 16593326 PMCID: PMC394054 DOI: 10.1073/pnas.80.11.3416] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Using partially deleted genes, we have identified an upstream control signal required for transcription of a Bombyx mori (silkworm) tRNA(2) (Ala) gene. The 5' boundary of this essential region lies between 34 and 11 nucleotides preceding the transcription initiation site. Sequences in the 5' half of the tRNA(2) (Ala) coding region are also important. Both regions contain oligonucleotides that are conserved among several Bombyx genes transcribed by RNA polymerase III, suggesting that these sequences may have a general control function.
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Affiliation(s)
- D Larson
- Institute of Molecular Biology and Department of Biology, University of Oregon, Eugene, Oregon 97403
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5
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Marrone A, Ballantyne J. Sequence specificity of BAL 31 nuclease for ssDNA revealed by synthetic oligomer substrates containing homopolymeric guanine tracts. PLoS One 2008; 3:e3595. [PMID: 18974878 PMCID: PMC2570716 DOI: 10.1371/journal.pone.0003595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Accepted: 10/09/2008] [Indexed: 11/18/2022] Open
Abstract
Background The extracellular nuclease from Alteromonas espejiana, BAL 31 catalyzes the degradation of single-stranded and linear duplex DNA to 5′-mononucleotides, cleaves negatively supercoiled DNA to the linear duplex form, and cleaves duplex DNA in response to the presence of apurinic sites. Principal Findings In this work we demonstrate that BAL 31 activity is affected by the presence of guanine in single-stranded DNA oligomers. Specifically, nuclease activity is shown to be affected by guanine's presence in minimal homopolymeric tracts in the middle of short oligomer substrates and also by its presence at the 3′ end of ten and twenty base oligomers. G•C rich regions in dsDNA are known to cause a decrease in the enzyme's nuclease activity which has been attributed to the increased thermal stability of these regions, thus making it more difficult to unwind the strands required for enzyme access. Our results indicate that an additional phenomenon could be wholly or partly responsible for the loss of activity in these G•C rich regions. Thus the presence of a guanine tract per se impairs the enzyme's functionality, possibly due to the tract's bulky nature and preventing efficient progression through the active site. Conclusions This study has revealed that the general purpose BAL 31 nuclease commonly used in molecular genetics exhibits a hithertofore non-characterized degree of substrate specificity with respect to single-stranded DNA (ssDNA) oligomers. Specifically, BAL 31 nuclease activity was found to be affected by the presence of guanine in ssDNA oligomers.
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Affiliation(s)
- April Marrone
- Graduate Program in Chemistry, Department of Chemistry, University of Central Florida, Orlando, Florida, United States of America
- National Center for Forensic Science, Orlando, Florida, United States of America
| | - Jack Ballantyne
- Graduate Program in Chemistry, Department of Chemistry, University of Central Florida, Orlando, Florida, United States of America
- National Center for Forensic Science, Orlando, Florida, United States of America
- * E-mail:
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6
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Liu GL, Yin Y, Kunchakarra S, Mukherjee B, Gerion D, Jett SD, Bear DG, Gray JW, Alivisatos AP, Lee LP, Chen FF. A nanoplasmonic molecular ruler for measuring nuclease activity and DNA footprinting. NATURE NANOTECHNOLOGY 2006; 1:47-52. [PMID: 18654141 DOI: 10.1038/nnano.2006.51] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Accepted: 08/29/2006] [Indexed: 05/26/2023]
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7
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Andreev VM, Gonikberg EM, Kuznetsova NV. A novel method of transfection of marine bacteria Pseudoalteromonas espejiana with deoxyribonucleic acid of bacteriophage PM2. RUSS J GENET+ 2006. [DOI: 10.1134/s1022795406070052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Abstract
Single-strand-specific nucleases are multifunctional enzymes and widespread in distribution. Their ability to act selectively on single-stranded nucleic acids and single-stranded regions in double-stranded nucleic acids has led to their extensive application as probes for the structural determination of nucleic acids. Intracellularly, they have been implicated in recombination, repair and replication, whereas extracellular enzymes have a role in nutrition. Although more than 30 single-strand-specific nucleases from various sources have been isolated till now, only a few enzymes (S1 nuclease from Aspergillus oryzae, P1 nuclease from Penicillium citrinum and nucleases from Alteromonas espejiana, Neurospora crassa, Ustilago maydis and mung bean) have been characterized to a significant extent. Recently, some of these enzymes have been cloned, their crystal structures solved and their interactions with different substrates have been established. The detection, purification, characteristics, structure-function correlations, biological role and applications of single-strand-specific nucleases are reviewed.
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Affiliation(s)
- Neelam A Desai
- Division of Biochemical Sciences, National Chemical Laboratory, 411008, Pune, India
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9
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Abstract
Sugar non-specific endonucleases are multifunctional enzymes and are widespread in distribution. Apart from nutrition, they have also been implicated in cellular functions like replication, recombination and repair. Their ability to recognize different DNA structures has also been exploited for the determination of nucleic acid structure. Although more than 30 non-specific endonucleases have been isolated to date, very little information is available regarding their structure-function correlations except that of staphylococcal and Serratia nucleases. However, during the past few years, the primary structure, nature of the active site based on sequence homology, and the probable mechanism of action have been postulated for some of the enzymes. This review describes the purification, characteristics, biological role and applications of sugar non-specific endonucleases.
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Affiliation(s)
- E S Rangarajan
- Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008, India
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10
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Tabor S, Struhl K. Endonucleases. CURRENT PROTOCOLS IN MOLECULAR BIOLOGY 2001; Chapter 3:Unit3.12. [PMID: 18265221 DOI: 10.1002/0471142727.mb0312s08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Reaction conditions for numerous endonucleases are detailed in this unit along with discussions of potential applications. Specific enzymes include BAL 31 nuclease, S1 nuclease, mung bean nuclease, micrococcal nuclease and DNase I.
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Affiliation(s)
- S Tabor
- Harvard Medical School, Boston, Massachusetts, USA
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11
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Knemeyer JP, Marmé N, Sauer M. Probes for detection of specific DNA sequences at the single-molecule level. Anal Chem 2000; 72:3717-24. [PMID: 10959954 DOI: 10.1021/ac000024o] [Citation(s) in RCA: 212] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A method has been developed for highly sensitive detection of specific DNA sequences in a homogeneous assay using labeled oligonucleotide molecules in combination with single-molecule photon burst counting and identification. The fluorescently labeled oligonucleotides are called smart probes because they report the presence of complementary target sequences by a strong increase in fluorescence intensity. The smart probes consist of a fluorescent dye attached at the terminus of a hairpin oligonucleotide. The presented technique takes advantage of the fact that the used oxazine dye JA242 is efficiently quenched by complementary guanosine residues. Upon specific hybridization to the target DNA, the smart probe undergoes a conformational change that forces the fluorescent dye and the guanosine residues apart, thereby increasing the fluorescence intensity about six fold in ensemble measurements. To increase the detection sensitivity below the nanomolar range, a confocal fluorescence microscope was used to observe the fluorescence bursts from individual smart probes in the presence and absence of target DNA as they passed through the focused laser beam. Smart probes were excited by a pulsed diode laser emitting at 635 nm with a repetition rate of 64 MHz. Each fluorescence burst was identified by three independent parameters: (a) the burst size, (b) the burst duration, and (c) the fluorescence lifetime. Through the use of this multiparameter analysis, higher discrimination accuracies between smart probes and hybridized probe-target duplexes were achieved. The presented multiparameter detection technique permits the identification of picomolar target DNA concentrations in a homogeneous assay, i.e., the detection of specific DNA sequences in a 200-fold excess of labeled probe molecules.
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Affiliation(s)
- J P Knemeyer
- Physicalisch-Chemsiches Institut, Universität Heidelberg, Germany
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12
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Kano Y, Nohno T, Takahashi R, Hiragami F, Kawamura K, Strebhardt K, Namba M, Sugiyama T, Little JB. Morphological alteration of X-ray induced partially transformed human cells by transfection with a small c-myc DNA sequence. Biochem Biophys Res Commun 2000; 272:887-94. [PMID: 10860847 DOI: 10.1006/bbrc.2000.2858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During attempts to transform a normal human fibroblast strain (GM730) by X-irradiation, we obtained a partially transformed cell strain (GM730pt) which demonstrates several aspects of the transformed phenotype including morphological changes, increased saturation density, growth in soft agar, and focus formation in long-term cultures. When GM730pt cells were transfected with the feline c-myc gene, morphology of the cells changed dramatically following seven days of expression. Transfection of other plasmid DNAs or oncogenes such as pUC8, pSV2neo, src, sis, and H-ras had little or no effects on the phenotype of GM730pt cells. On the other hand, a gel purified, small fragment of c-myc DNA had a complete cell alteration activity. Furthermore, Bal 31 deletion and M13 sequencing experiments showed that the alteration seen in GM730pt cells is delimited to a 24 nucleotide stretch (active myc element) from the second intron of the feline c-myc gene that contains a T-rich sequence.
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Affiliation(s)
- Y Kano
- Department of Health Science, Kibi International University, Okayama, Japan
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13
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Abstract
The genome of adenovirus (AV) types 1, 2, and 5 is known to be very variable as evidenced by the great number of genome types described (36, 61, and 35 for AV1, 2, and 5 respectively). Physical maps were constructed for nearly all of the restriction or R-variants by biochemical methods and by adapting restriction fragments of defined molecular weight. The alterations found with seven DNA restriction endonucleases were mapped on the genome. Altered restriction sites, found for the genome types of each of the three serotypes, appeared to be randomly distributed over the genome, although mutations seemed to occur preferentially on distinct sites of the genome. Many strains, especially those of AV5, were genomically much more related with one another than with the prototype. This finding is compatible with the interpretation that the related strains were derived from an unknown common ancestor.
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Affiliation(s)
- T Adrian
- Nationales Referenzzentrum für Adenoviren, Medizinische Hochschule Hannover, Federal Republic of Germany
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14
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Somoskeöy S, Rao MN, Slobin LI. Purification and characterization of a 5' to 3' exoribonuclease from rabbit reticulocytes that degrades capped and uncapped RNAs. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 237:171-9. [PMID: 8620871 DOI: 10.1111/j.1432-1033.1996.0171n.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The cytoplasm of mammalian cells of undoubtedly contain a number of different ribonuclease activities, few if any of which have been well characterized. We describe the purification of an exoribonuclease from rabbit reticulocytes which is able to degrade capped RNAs in a 5' to 3' manner. The purified enzyme contains polypeptides of 62 and 58 kDa and may contain an additional polypeptide of 54 kDa. It behaves as a complex of 150 kDa when analyzed by HPLC gel retardation on Superdex 200HR. It is heat-labile, dependent upon divalent cations (Mg2+) for activity, resistant to placental ribonuclease inhibitor, and active over a broad range (10-200 mM) of monovalent cation (K+) concentrations. The enzyme requires a polynucleotide chain of at least 10 bases for activity and cleaves oligonucleotides, up to an octamer long, from the 5' end of an appropriate substrate. In the case of a capped RNA substrate, product analysis by TLC and PAGE indicates that a capped trinucleotide or tetranucleotide or both is produced. Examination of the kinetics of the enzyme with capped and triphosphate-terminated substrates shows that that the cap structure inhibits the action of the enzyme. Furthermore, the data suggest that the rate-limiting step involves the positioning of the enzyme at the 5' end of the substrate and/or cleavage of the first internucleotide bond.
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Affiliation(s)
- S Somoskeöy
- Department of Biochemistry, University of Mississippi School of Medicine, Jackson 39216, USA
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15
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Liu Z, Yang D, Qiu Z, Lim KT, Chong P, Gillam S. Identification of domains in rubella virus genomic RNA and capsid protein necessary for specific interaction. J Virol 1996; 70:2184-90. [PMID: 8642641 PMCID: PMC190057 DOI: 10.1128/jvi.70.4.2184-2190.1996] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In rubella virus-infected cells, genomic 40S and subgenomic 24S RNAs are present in the cytoplasm of infected cells. However, encapsidation by rubella virus capsid protein is specific for 40S genomic RNA. As a first step toward understanding the assembly of rubella virus nucleocapsid at the molecular level, the interaction between capsid protein and genomic RNA was studied by Northwestern (RNA-protein) blot analysis. RNA probes prepared by in vitro transcription were used to localize the RNA sequence that participates in binding to the capsid protein. We have identified a 29-nucleotide RNA sequence (nucleotides 347 to 375) that is essential for the binding. By using overlapping synthetic peptides of capsid protein, a peptide domain (residues 28 to 56) that displays specific RNA-binding activity of capsid protein has been located. This result suggests that the specific recognition of viral RNA during rubella virus assembly involves, at least in part, the nucleocapsid protein.
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Affiliation(s)
- Z Liu
- Department of Pathology and Laboratory Medicine, University of British Columbia Research Centre, Vancouver, British Columbia, Canada
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16
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Fomenkov A, Xu SY. Cloning of a gene from Thermus filiformis and characterization of the thermostable nuclease. Gene 1995; 163:109-13. [PMID: 7557458 DOI: 10.1016/0378-1119(95)00426-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A gene coding for a thermostable nuclease was cloned from the thermophilic microorganism, Thermus filiformis (Tf), using an indicator strain containing a dinD::lacZ fusion. The gene, designated nuc17, has been mapped within a 2300-bp fragment. The 55-kDa Tf nuclease was purified to over 95% homogeneity. Single-stranded (ss) DNA is the preferred substrate for the Tf nuclease, although double-stranded (ds) DNA can also be digested. Nuclease activity increases with increasing temperature up to 80 degrees C and requires the metal ions Ca++ or Mg++ for catalysis. Tf nuclease is primarily an endonuclease that leaves 5' phosphates in the digested products. The ssDNA extensions remaining after exonuclease III digestion of dsDNA can be removed by the Tf nuclease, making it a useful reagent to generate unidirectional deletions.
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Affiliation(s)
- A Fomenkov
- New England Biolabs Inc., Beverly, MA 01915, USA
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17
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[22] Use of PCR in analysis of 5′-flanking region of androgen receptor gene. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/s1043-9471(06)80100-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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18
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Abstract
Single-strand-specific nucleases, which act on single-stranded nucleic acids and single-stranded regions in double-stranded nucleic acids, are multifunctional enzymes and are ubiquitous in distribution. They find wide application as analytical tools in molecular biology research, although enzymes such as P1 nuclease are also used for production of flavor enhancers such as 5' IMP and 5' GMP. Because these enzymes are mainly used as analytical tools, very little attention was paid to aspects relating to their structure-function relationships. However, during the last few years considerable developments have taken place in this area. Single-strand-specific nucleases, their purification, characteristics, biological role, and applications have been reviewed.
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Affiliation(s)
- S U Gite
- Division of Biochemical Sciences, National Chemical Laboratory, Pune, India
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19
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Kim AY, Blaschek HP. Construction and characterization of a phage-plasmid hybrid (phagemid), pCAK1, containing the replicative form of viruslike particle CAK1 isolated from Clostridium acetobutylicum NCIB 6444. J Bacteriol 1993; 175:3838-43. [PMID: 8509336 PMCID: PMC204800 DOI: 10.1128/jb.175.12.3838-3843.1993] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A bacteriophage-plasmid hybrid (phagemid) designated pCAK1 was constructed by ligating 5-kbp Escherichia coli plasmid pAK102 (AprEmr) and the 6.6-kbp HaeIII-linearized replicative form of the CAK1 viruslike particle from Clostridium acetobutylicum NCIB 6444. Phagemid pCAK1 (11.6 kbp) replicated via the ColE1 replication origin derived from pAK102 in E. coli. Single-stranded DNA (ssDNA) molecules complexed with protein in a manner which protected ssDNA from nucleases were recovered from the supernatant of E. coli DH11S transformants containing pCAK1 in the absence of cell lysis. This suggests that the viral-strand DNA synthesis replication origin of CAK1 and associated gene expression are functional in E. coli DH11S. The single-stranded form of pCAK1 isolated from E. coli supernatant was transformed into E. coli DH5 alpha' or DH11S by electroporation. Isolation of ampicillin-resistant E. coli transformants following transformation suggests that the complementary-strand DNA synthesis replication origin of CAK1 is also functional in E. coli. The coat proteins associated with ssDNA of pCAK1 demonstrated sensitivity to proteinase K and various solvents (i.e., phenol and chloroform), similar to the results obtained previously with CAK1. Following phagemid construction in E. coli, pCAK1 was transformed into C. acetobutylicum ATCC 824 and C. perfringens 13 by intact cell electroporation. Restriction enzyme analysis of pCAK1 isolated from erythromycin-resistant transformants of both C. acetobutylicum and C. perfringens suggested that it was identical to that present in E. coli transformants.
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Affiliation(s)
- A Y Kim
- Department of Food Science, University of Illinois, Urbana 61801
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20
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Hauser MA, Scocca JJ. Site-specific integration of the Haemophilus influenzae bacteriophage HP1: location of the boundaries of the phage attachment site. J Bacteriol 1992; 174:6674-7. [PMID: 1383194 PMCID: PMC207650 DOI: 10.1128/jb.174.20.6674-6677.1992] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Plasmids containing DNA segments from the attachment region of phage HP1 were constructed and tested for the ability to replace the phage attachment site substrate in site-specific recombination reactions. The distance separating the boundaries of the functional site was 418 bp. Replacements within the 11-residue segment 5'-GGCGGTTATCG at the left boundary or within the 12-residue segment 5'-GGATTTTTTGAA at the right boundary abolished substrate activity. A segment of the 418-residue sequence preserves the integrity of an operon of three Haemophilus influenzae tRNA genes after HP1 insertion within the coding sequence.
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Affiliation(s)
- M A Hauser
- Department of Biochemistry, Johns Hopkins University School of Hygiene and Public Health, Baltimore, Maryland 21205
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21
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Abstract
We describe a novel procedure for the construction of deletion mutants. Existing exonuclease-based protocols are efficient at producing randomly positioned deletions over large regions of DNA, but are of limited use in targetted mutagenesis due to their inherent sequence-specificity. We have taken advantage of the Exonuclease III-resistant nature of alpha-thio-dNTPs, incorporated into the target DNA template by a primer extension reaction, to generate base-specific alpha-thio-dNTP terminated products. Following removal of the 5' overhanging strands, the products can be cloned to generate a nested set of deletions with single base-pair increments. We demonstrate the utility of this technique by isolating multiple deletions over a 40bp region of the human beta-interferon promoter.
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Affiliation(s)
- P King
- Gene Expression Laboratory, Imperial Cancer Research Fund, London, UK
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22
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Lee H, Kraus KW, Wolfner MF, Lis JT. DNA sequence requirements for generating paused polymerase at the start of hsp70. Genes Dev 1992; 6:284-95. [PMID: 1737619 DOI: 10.1101/gad.6.2.284] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
RNA polymerase II is transcriptionally engaged but paused approximately 25 nucleotides from the start site of the hsp70 gene of Drosophila melanogaster in uninduced (non-heat-shocked) flies. Here, we identify regions of the hsp70 promoter that are required for formation of this paused polymerase. Various hsp70 promoter sequences are substituted for promoter sequences of a yolk protein gene, yp1, which, in males, is normally not expressed and has no paused polymerase. Run-on assays with nuclei of male transgenic flies are used to measure the level of paused polymerase on the hybrid genes. Sequences that reside upstream of the hsp70 TATA element, when fused upstream of the yp1 TATA element, specify the formation of a paused polymerase on the 5' end of this hybrid gene. Within this region are multiple copies of the GAGA element, which is known to bind a constitutively expressed factor. This element appears to play a role in generating the pause. Also, in the absence of much of this upstream region, hsp70 sequences in the vicinity of the transcriptional start and pause site participate in specifying the pause. Deletions of the pause site reduce the level of paused polymerase but do not lead to constitutive transcription. However, a connection between transcription and pausing is seen. The level of paused polymerase on the various hybrid hsp70-yp1 promoters correlates with the promoter's potential to direct heat-induced transcription.
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Affiliation(s)
- H Lee
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853
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23
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Kobayashi M, Nishiyama M, Nagasawa T, Horinouchi S, Beppu T, Yamada H. Cloning, nucleotide sequence and expression in Escherichia coli of two cobalt-containing nitrile hydratase genes from Rhodococcus rhodochrous J1. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1129:23-33. [PMID: 1840499 DOI: 10.1016/0167-4781(91)90208-4] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Rhodococcus rhodochrous J1 produces two kinds of cobalt-containing nitrile hydratases (NHases); one is a high molecular mass-NHase (H-NHase) and the other is a low molecular mass-NHase (L-NHase). Both NHases are composed of two subunits of different sizes (alpha and beta subunits). The H- and L-NHase genes were cloned into Escherichia coli by a DNA-probing method using the NHase gene of Rhodococcus sp. N-774, a ferric ion-containing NHase producing strain, as the hybridization probe and their nucleotide sequences were determined. In each of the H- and L-NHase genes, the open reading frame for the beta subunit was located just upstream of that for the alpha subunit, which probably belongs to the same operon. The amino acid sequences of each subunit of the H- and L-NHases from R. rhodochrous J1 showed generally significant similarities to those from Rhodococcus sp. N-774, but the arrangement of the coding sequences for two subunits is reverse of the order found in the NHase gene of Rhodococcus sp. N-774. Each of the NHase genes was expressed in E. coli cells under the control of lac promoter, only when they were cultured in the medium supplemented with CoCl2.
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Affiliation(s)
- M Kobayashi
- Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Japan
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24
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IJdo JW, Baldini A, Ward DC, Reeders ST, Wells RA. Origin of human chromosome 2: an ancestral telomere-telomere fusion. Proc Natl Acad Sci U S A 1991; 88:9051-5. [PMID: 1924367 PMCID: PMC52649 DOI: 10.1073/pnas.88.20.9051] [Citation(s) in RCA: 223] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have identified two allelic genomic cosmids from human chromosome 2, c8.1 and c29B, each containing two inverted arrays of the vertebrate telomeric repeat in a head-to-head arrangement, 5'(TTAGGG)n-(CCCTAA)m3'. Sequences flanking this telomeric repeat are characteristic of present-day human pretelomeres. BAL-31 nuclease experiments with yeast artificial chromosome clones of human telomeres and fluorescence in situ hybridization reveal that sequences flanking these inverted repeats hybridize both to band 2q13 and to different, but overlapping, subsets of human chromosome ends. We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2.
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Affiliation(s)
- J W IJdo
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510
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25
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Strickland JA, Marzilli LG, Puckett JM, Doetsch PW. Purification and properties of nuclease SP. Biochemistry 1991; 30:9749-56. [PMID: 1655020 DOI: 10.1021/bi00104a026] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Single-strand-specific nucleases are a diverse and important group of enzymes that are able to cleave a variety of DNA structures present in duplex molecules. Nuclease SP, an enzyme from spinach, has been purified to apparent homogeneity, allowing for the unambiguous characterization of a number of its physical properties as well as its DNA strand cleavage specificities. The effects of ionic strength, pH, divalent metal cations, and temperature on nuclease SP activity have been examined in detail. Nuclease SP was found to be quite thermostable and could be stimulated by Co2+. In addition, the cleavage of UV-damaged and undamaged supercoiled plasmid substrates under a variety of conditions suggests that at least two types of structures are recognized and processed by nuclease SP: UV photoproduct-induced distortions and unwound "nuclease hypersensitive sites". These studies indicate that nuclease SP is functionally related to other single-strand-specific nucleases and is a potential enzymatic tool for probing and manipulating various types of DNA structures.
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Affiliation(s)
- J A Strickland
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, Georgia 30322
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26
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Hauser CR, Gray HB. Vectors containing infrequently cleaved restriction sites for use in BAL 31 nuclease-assisted and end-label-mediated analysis of cloned DNA fragments. GENETIC ANALYSIS, TECHNIQUES AND APPLICATIONS 1991; 8:139-47. [PMID: 1931183 DOI: 10.1016/1050-3862(91)90022-j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cloning vectors derived from plasmids pUC8 and pUC18 and phage M13mp10 were constructed so as to have multiple cloning sites (MCS) flanked by the recognition/cleavage sites for the Sfi I and Not I restriction nucleases. Cleavage of vectors containing cloned DNA fragments with either of the infrequently cleaving Sfi I or Not I endonucleases will usually yield linear DNAs cleaved only at the corresponding site in the MCS, so that the cloned insert can be degraded unidirectionally by the duplex exonuclease activity of the BAL 31 nucleases until an amount equal to the length of the vector has been degraded. The ends of the above constructs resulting from cleavage with Not I or Sfi I can readily be labeled, with labeling at only the terminus of the cloned DNA available for the Sfi I site. The BAL 31 nuclease-mediated procedures enhance a previous technique for mapping of restriction enzyme fragments, allow for localization of sequences in cloned segments for which a probe is available, and improve a method for sequencing cloned inserts through the production of sets of nested unidirectional deletions from either end of the parent cloned fragment. The advantages of end-label-mediated restriction site mapping using the above vectors over existing such procedures are also demonstrated.
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Affiliation(s)
- C R Hauser
- Department of Biochemical and Biophysical Sciences, University of Houston, Texas 77204-5934
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27
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Murphy E, Reinheimer E, Huwyler L. Mutational analysis of att554, the target of the site-specific transposon Tn554. Plasmid 1991; 26:20-9. [PMID: 1658834 DOI: 10.1016/0147-619x(91)90033-s] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Tn554 is a high-frequency, site-specific transposable element of Staphylococcus aureus which has integrative properties resembling those of temperate bacteriophages. Tn554 inserts at a unique chromosomal location, designated att554. att554 contains a core hexanucleotide sequence, 5'-GATGTA-3' (nucleotides numbered -3 to +3). Most of the time (greater than 99%) insertion occurs immediately 3' to this sequence; the resulting orientation of Tn554 to att554 is designated as the (+) orientation. Infrequent insertions immediately 5' to the core sequence result in the opposite, or (-) orientation. Mutational analysis of a cloned att554 site indicates that deletions extending from the left and ending at -15 or from the right ending between +8 and +12 reduced attachment site efficiency. Plasmids with deletions extending closer to the insertion site, although still retaining the core sequence from -3 to +3, were totally inactive. Tn554 insertions into partially active att554 sites retained normal site- and orientation-specificity with respect to att554, but they frequently contained abnormal sequences at the junction of att554 and the 3' end of Tn554. These data indicate that att554 contains a short nucleotide sequence essential for transposition and flanking sequences that greatly increase the frequency of recombination.
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Affiliation(s)
- E Murphy
- Public Health Research Institute, New York, New York 10016
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28
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Schnorr KM, Juricek M, Huang CX, Culley D, Kleinhofs A. Analysis of barley nitrate reductase cDNA and genomic clones. MOLECULAR & GENERAL GENETICS : MGG 1991; 227:411-6. [PMID: 1865878 DOI: 10.1007/bf00273931] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Barley nitrate reductase cDNA and genomic clones were isolated by homology with the barley nitrate reductase cDNA clone bNRp10 and sequenced. This is the first reported analysis of a full-length nitrate reductase gene and its corresponding cDNA in the same species. The longest cDNA clone extends to within 9 bp of the ATG start codon and the sequence is similar to that reported for the higher plant NR sequences. As expected, the amino acid sequence of barley nitrate reductase is more related closely to the rice (84% homology) than to the Arabidopsis (62%) sequence. Four different polyA addition sites were identified from sequence analysis of nine barley NR cDNA clones. A 7.3 kb region of a genomic recombinant lambda clone was subcloned as two contiguous BamHI fragments into p Bluescript, designated pMJ7 and pMJ8, and sequenced. These clones include the entire nitrate reductase coding region, one large intron, 2.7 kb of untranslated sequence 5' to the translation start codon and 0.25 kb 3' to the translation termination codon. The mRNA cap site was identified as a cytosine, 111 bases upstream of the ATG translation start codon. The putative CAAT and TATA boxes were identified at -115 and -33 bp, respectively, with the mRNA cap site designated as +1. The barley nitrate reductase gene coding region strongly favors G or C in the third codon position.
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Affiliation(s)
- K M Schnorr
- Dept. of Crop and Soil Sciences, Washington State University, Pullman 99164-6420
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29
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Abstract
A DNA structure is defined as paranemic if the participating strands can be separated without mutual rotation of the opposite strands. The experimental methods employed to detect paranemic, unwound, DNA regions is described, including probing by single-strand specific nucleases (SNN), conformation-specific chemical probes, topoisomer analysis, NMR, and other physical methods. The available evidence for the following paranemic structures is surveyed: single-stranded DNA, slippage structures, cruciforms, alternating B-Z regions, triplexes (H-DNA), paranemic duplexes and RNA, protein-stabilized paranemic DNA. The problem of DNA unwinding during gene copying processes is analyzed; the possibility that extended paranemic DNA regions are transiently formed during replication, transcription, and recombination is considered, and the evidence supporting the participation of paranemic DNA forms in genes committed to or undergoing copying processes is summarized.
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MESH Headings
- Animals
- Base Sequence
- Chromosomes/ultrastructure
- DNA/drug effects
- DNA/metabolism
- DNA/ultrastructure
- DNA Helicases/metabolism
- DNA Replication
- DNA Topoisomerases, Type I/metabolism
- DNA Topoisomerases, Type II/metabolism
- DNA, Single-Stranded/drug effects
- DNA, Single-Stranded/metabolism
- DNA, Single-Stranded/ultrastructure
- DNA, Superhelical/drug effects
- DNA, Superhelical/metabolism
- DNA, Superhelical/ultrastructure
- DNA-Binding Proteins/metabolism
- Endonucleases/metabolism
- Models, Genetic
- Molecular Sequence Data
- Nucleic Acid Conformation/drug effects
- Nucleic Acid Denaturation
- Plasmids
- Transcription, Genetic
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Affiliation(s)
- G Yagil
- Department of Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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30
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Henriquez V, Gennaro ML. A simple strategy to generate small deletions using Bal31 nuclease. Nucleic Acids Res 1990; 18:6735-6. [PMID: 2251158 PMCID: PMC332677 DOI: 10.1093/nar/18.22.6735] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- V Henriquez
- Public Health Research Institute, New York, NY 10016
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31
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Adrian T, Wolf U, Lauer HJ, Wigand R. Restriction site mapping of adenovirus type 8 genome types. RESEARCH IN VIROLOGY 1990; 141:611-24. [PMID: 2087599 DOI: 10.1016/0923-2516(90)90034-g] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The DNA of 60 adenovirus type 8 (AV8) isolates (collected during the period 1961 to 1982, mostly in Western Germany) was analysed by 6 endonucleases and revealed 6 different genome types, thus implying that the variability of AV8 is relatively low. It was found that 45 isolates belonged to the genome type D1. Restriction site maps of a prototype D1 and of all deviating restriction variants were elaborated for enzymes BamHI, BglII, Hind-III and SalI.
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Affiliation(s)
- T Adrian
- Nationales Referenzzentrum für Adenoviren, Institut für Virologie und Seuchenhygiene, Medizinische Hochschule, Hannover, Germany
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32
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Nucleocytoplasmic transport and processing of small nuclear RNA precursors. Mol Cell Biol 1990. [PMID: 2355910 DOI: 10.1128/mcb.10.7.3365] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have analyzed the structures and locations of small nuclear RNA (snRNA) precursors at various stages in their synthesis and maturation. In the nuclei of pulse-labeled Xenopus laevis oocytes, we detected snRNAs that were longer than their mature forms at their 3' ends by up to 10 nucleotides. Analysis of the 5' caps of these RNAs and pulse-chase experiments showed that these nuclear snRNAs were precursors of the cytoplasmic pre-snRNAs that have been observed in the past. Synthesis of pre-snRNAs was not abolished by wheat germ agglutinin, which inhibits export of the pre-snRNAs from the nucleus, indicating that synthesis of these RNAs is not obligatorily coupled to their export. Newly synthesized U1 RNAs could be exported from the nucleus regardless of the length of the 3' extension, but pre-U1 RNAs that were elongated at their 3' ends by more than about 10 nucleotides were poor substrates for trimming in the cytoplasm. The structure at the 3' end was critical for subsequent transport of the RNA back to the nucleus. This requirement ensures that truncated and incompletely processed U1 RNAs are excluded from the nucleus.
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33
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Wickner S, Hoskins J, Chattoraj D, McKenney K. Deletion analysis of the mini-P1 plasmid origin of replication and the role of Escherichia coli DnaA protein. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38443-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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34
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Neuman de Vegvar HE, Dahlberg JE. Nucleocytoplasmic transport and processing of small nuclear RNA precursors. Mol Cell Biol 1990; 10:3365-75. [PMID: 2355910 PMCID: PMC360761 DOI: 10.1128/mcb.10.7.3365-3375.1990] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We have analyzed the structures and locations of small nuclear RNA (snRNA) precursors at various stages in their synthesis and maturation. In the nuclei of pulse-labeled Xenopus laevis oocytes, we detected snRNAs that were longer than their mature forms at their 3' ends by up to 10 nucleotides. Analysis of the 5' caps of these RNAs and pulse-chase experiments showed that these nuclear snRNAs were precursors of the cytoplasmic pre-snRNAs that have been observed in the past. Synthesis of pre-snRNAs was not abolished by wheat germ agglutinin, which inhibits export of the pre-snRNAs from the nucleus, indicating that synthesis of these RNAs is not obligatorily coupled to their export. Newly synthesized U1 RNAs could be exported from the nucleus regardless of the length of the 3' extension, but pre-U1 RNAs that were elongated at their 3' ends by more than about 10 nucleotides were poor substrates for trimming in the cytoplasm. The structure at the 3' end was critical for subsequent transport of the RNA back to the nucleus. This requirement ensures that truncated and incompletely processed U1 RNAs are excluded from the nucleus.
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35
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Kim AY, Vertes AA, Blaschek HP. Isolation of a single-stranded plasmid from Clostridium acetobutylicum NCIB 6444. Appl Environ Microbiol 1990; 56:1725-8. [PMID: 2383010 PMCID: PMC184500 DOI: 10.1128/aem.56.6.1725-1728.1990] [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: 12/31/2022] Open
Abstract
The cryptic plasmid pDM6 was isolated from late exponential-phase cells of Clostridium acetobutylicum NCIB 6444 by either alkaline lysis or electroporation. The application of high voltage during electroporation resulted in higher DNA yield than did the alkaline lysis procedure. However, electroporation-induced plasmid release generated high amounts of single-stranded DNA compared with the alkaline lysis procedure, which generated both double-stranded DNA (monomer and dimer forms) and single-stranded DNA.
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Affiliation(s)
- A Y Kim
- Department of Food Science, University of Illinois, Urbana 61801
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36
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A liver-specific nuclear factor interacts with the promoter region of the large surface protein gene of human hepatitis B virus. Mol Cell Biol 1990. [PMID: 2601716 DOI: 10.1128/mcb.9.11.5189] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The outer envelope of the 42-nm virion of the human hepatitis B virus (HBV) is composed of the large, the middle, and the major surface proteins. Whereas the middle and the major surface proteins are transcribed from the SPII promoter of the pre-S/S gene, the large surface protein is transcribed from the SPI promoter located upstream of SPII. We have previously shown that transcription of SPI (comprising nucleotides [nt] -380 to +17) occurs preferentially in differentiated hepatoma cell lines (H.K. Chang and L.P. Ting, Virology 170:176-183, 1989). In this report, we further demonstrated that a sequence of 95 base pairs in the upstream region of SPI (nt -95 to +17) was necessary and sufficient for such preferential expression in differentiated hepatoma cells. By analysis of the expression of the chloramphenicol acetyltransferase gene in a series of mutants with deletions at the 5' end of SPI, we identified a positive transcriptional cis-acting element mapping at nt -95 to -72 which appears to play a key role in the regulation of the expression of the large surface protein. This region shared a high degree of sequence homology with regulatory sequences of several liver-specific genes from human, mouse, and rat, with a consensus sequence (G/A)GTTA(A/C)TNNT(C/T)NNC(A/C). We further identified a nuclear factor present in the nuclear extracts of differentiated human hepatoma cell lines which interacted specifically with this element of the SPI promoter. This nuclear factor was similar to the rat liver-specific factor HNF-1, since an oligonucleotide containing the recognition sequence of HNF-1 could efficiently compete for the human factor in a footprinting assay. The sequence at nt -93 to -68 which was bound by this factor in SPI was termed the HNF-1-binding element. Activation of the SPI promoter by human differentiated hepatocyte nuclear factor 1, described in this report, probably explains, first, the formation of the 42-nm virion specifically in liver but not in several other tissues despite the synthesis of the middle and the major surface proteins in those tissues, and second, why only differentiated hepatoma cell lines are able to produce 42-nm-like virion particles on transfection by HBV DNA.
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37
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Guzman P, Rivera Chavira BE, Court DL, Gottesman ME, Guarneros G. Transcription of a bacteriophage lambda DNA site blocks growth of Escherichia coli. J Bacteriol 1990; 172:1030-4. [PMID: 2137118 PMCID: PMC208533 DOI: 10.1128/jb.172.2.1030-1034.1990] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The rap mutation in Escherichia coli prevents the growth of bacteriophage lambda. Phage mutations that overcome rap inhibition (bar) have been mapped to loci in the pL operon. We cloned and sequenced three mutations in two of these loci: barIa to the left arm of the lambda attachment site (attP) and barII in the ssb (ea10) gene. The mutations represent single base-pair changes within nearly identical 16-base-pair DNA segments. Each mutation disrupts a sequence of dyad symmetry within the segment. Plasmids carrying a bar+ sequence downstream to an active promoter are lethal to rap, but not rap+, bacteria. The bar sequences isolated from the lambda bar mutants are not lethal. We synthesized a minimal lambda barIa+ sequence, 5'-TATATTGATATTTATATCATT, and cloned it downstream to an inducible promoter. When transcribed, this sequence is sufficient to kill a rap strain.
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Affiliation(s)
- P Guzman
- Centro de Investigación y de Estudios Avanzados del IPN, Mexico D.F., Mexico
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38
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Tobin SL, Cook PJ, Burn TC. Transcripts of individual Drosophila actin genes are differentially distributed during embryogenesis. DEVELOPMENTAL GENETICS 1990; 11:15-26. [PMID: 1694472 DOI: 10.1002/dvg.1020110104] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The temporal and spatial patterns of accumulation of transcripts from individual actin genes during Drosophila embryogenesis have been determined by in situ hybridization. We describe the subcloning into transcription vectors of unique DNA fragments derived from the 3' transcribed, but nontranslated region of each actin gene. These fragments then served as templates for the synthesis in vitro of single-stranded, radio-active gene-specific RNA probes. Probe characterization and hybridization to developmental RNA blots are presented, demonstrated the independent developmental accumulation of actin transcripts from each gene. Each gene-specific probe has been hybridized in situ to the transcripts present in embryonic frozen sections. The results of these experiments have demonstrated that transcripts from each actin gene accumulate differentially in developing Drosophila tissues. The 5C and 42A actin genes are cytoplasmic actin genes, with transcripts distributed in all cells and tissues of the developing embryo. Therefore these genes presumably encode the cytoplasmic actins used for functions common to all cells. Transcripts from both cytoplasmic actin genes are evenly distributed in preblastoderm embryos, becoming localized to the periphery at blastoderm formation [5C: Burn et al.: Dev Biol 131:345-355, 1989]. Later in development, levels of these cytoplasmic transcripts vary in specific tissues. While the patterns of localization of 5C actin transcripts have been published [Burn et al.: Dev Biol 131:345-355, 1989], differential neurological localization is presented here; 42A transcripts are localized at higher concentrations in the midgut, the brain, nerve cord, and gonad. Both 87E and 57B transcripts accumulated in the developing larval body wall musculature, but at differing levels and in differing patterns. Transcripts of the 79B and the 88F actin genes were undetectable in embryos. The results of these experiments suggest dedicated contributions of individual actin genes to complex developmental processes.
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Affiliation(s)
- S L Tobin
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City 73190
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39
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Fabiani L, Aragona M, Frontali L. Isolation and sequence analysis of a K. lactis chromosomal DNA element able to autonomously replicate in S. cerevisiae and K. lactis. Yeast 1990; 6:69-76. [PMID: 2180237 DOI: 10.1002/yea.320060108] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We have undertaken a search for autonomously replicating (ARSs) from Kluyveromyces lactis chromosomal DNA able to sustain plasmid replication in K. lactis and in Saccharomyces cerevisiae. The discovery of such sequences might be interesting for the comparison of ARSs from different sources and possibly useful for the construction of multivalent vectors. HindIII fragments from K. lactis chromosomal DNA were inserted in the YIp5 plasmid (lacking an origin of replication) and the resulting chimaeric plasmids were selected for the ability to transform S. cerevisiae. Four plasmids were identified and further analysed. Two contained the same 1.8 kb K. lactis fragment and transformed both K. lactis and S. cerevisiae with the same efficiency and stability, whereas the third transformed only S. cerevisiae and the fourth transformed K. lactis with a higher efficiency than S. cerevisiae. A detailed study was performed on the 1.8 kb fragment which exhibited ARS function in both yeasts. The fragment was subcloned using different restriction enzymes and Bal31 exonuclease. Subclones were tested for ARS function. ARS activities in the two yeasts were localized in the same 100 bp region. Sequencing demonstrated the presence in this region of the dodecanucleotide 5'ATTTATTGTTTT3' differing from the ARS core consensus of S. cerevisiae only by a T insertion. A similar nucleotide sequence is present in the putative replication origin of the 2 mu-like plasmid pKD1 which stably replicates in K. lactis. Homologies with ARSs from S. cerevisiae were also found in the regions flanking the above-mentioned dodecanucleotide.
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Affiliation(s)
- L Fabiani
- Department of Cell and Developmental Biology, University of Rome La Sapienza, Italy
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40
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Adrian T, Wolf U. Adenovirus 6 genome types: mapping of restriction site alterations on the genome. RESEARCH IN VIROLOGY 1989; 140:545-50. [PMID: 2616903 DOI: 10.1016/s0923-2516(89)80140-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- T Adrian
- Abteilung für Virologie, Universitätskliniken, Homburg, Saar, FRG
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41
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Chang HK, Wang BY, Yuh CH, Wei CL, Ting LP. A liver-specific nuclear factor interacts with the promoter region of the large surface protein gene of human hepatitis B virus. Mol Cell Biol 1989; 9:5189-97. [PMID: 2601716 PMCID: PMC363671 DOI: 10.1128/mcb.9.11.5189-5197.1989] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The outer envelope of the 42-nm virion of the human hepatitis B virus (HBV) is composed of the large, the middle, and the major surface proteins. Whereas the middle and the major surface proteins are transcribed from the SPII promoter of the pre-S/S gene, the large surface protein is transcribed from the SPI promoter located upstream of SPII. We have previously shown that transcription of SPI (comprising nucleotides [nt] -380 to +17) occurs preferentially in differentiated hepatoma cell lines (H.K. Chang and L.P. Ting, Virology 170:176-183, 1989). In this report, we further demonstrated that a sequence of 95 base pairs in the upstream region of SPI (nt -95 to +17) was necessary and sufficient for such preferential expression in differentiated hepatoma cells. By analysis of the expression of the chloramphenicol acetyltransferase gene in a series of mutants with deletions at the 5' end of SPI, we identified a positive transcriptional cis-acting element mapping at nt -95 to -72 which appears to play a key role in the regulation of the expression of the large surface protein. This region shared a high degree of sequence homology with regulatory sequences of several liver-specific genes from human, mouse, and rat, with a consensus sequence (G/A)GTTA(A/C)TNNT(C/T)NNC(A/C). We further identified a nuclear factor present in the nuclear extracts of differentiated human hepatoma cell lines which interacted specifically with this element of the SPI promoter. This nuclear factor was similar to the rat liver-specific factor HNF-1, since an oligonucleotide containing the recognition sequence of HNF-1 could efficiently compete for the human factor in a footprinting assay. The sequence at nt -93 to -68 which was bound by this factor in SPI was termed the HNF-1-binding element. Activation of the SPI promoter by human differentiated hepatocyte nuclear factor 1, described in this report, probably explains, first, the formation of the 42-nm virion specifically in liver but not in several other tissues despite the synthesis of the middle and the major surface proteins in those tissues, and second, why only differentiated hepatoma cell lines are able to produce 42-nm-like virion particles on transfection by HBV DNA.
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Affiliation(s)
- H K Chang
- Graduate Institute of Microbiology and Immunology, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China
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42
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Loprasert S, Negoro S, Okada H. Cloning, nucleotide sequence, and expression in Escherichia coli of the Bacillus stearothermophilus peroxidase gene (perA). J Bacteriol 1989; 171:4871-5. [PMID: 2670897 PMCID: PMC210291 DOI: 10.1128/jb.171.9.4871-4875.1989] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The gene encoding a thermostable peroxidase was cloned from the chromosomal DNA of Bacillus stearothermophilus IAM11001 in Escherichia coli. The nucleotide sequence of the 3.1-kilobase EcoRI fragment containing the peroxidase gene (perA) and its flanking region was determined. A 2,193-base-pair open reading frame encoding a peroxidase of 731 amino acid residues (Mr, 82,963) was observed. A Shine-Dalgarno sequence was found 9 base pairs upstream from the translational starting site. The deduced amino acid sequence coincides with those of the amino terminus and four peptides derived from the purified peroxidase of B. stearothermophilus IAM11001. E. coli harboring a recombinant plasmid containing perA produced a large amount of thermostable peroxidase which comigrated on polyacrylamide gel electrophoresis with the B. stearothermophilus peroxidase. The peroxidase of B. stearothermophilus showed 48% homology in the amino acid sequence to the catalase-peroxidase of E. coli.
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Affiliation(s)
- S Loprasert
- Department of Fermentation Technology, Osaka University, Japan
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43
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Multiple hepatocyte-enriched nuclear factors function in the regulation of transthyretin and alpha 1-antitrypsin genes. Mol Cell Biol 1989. [PMID: 2786140 DOI: 10.1128/mcb.9.4.1415] [Citation(s) in RCA: 321] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transthyretin (TTR) and alpha 1-antitrypsin (alpha 1-AT) are expressed at high levels in the liver and also in at least one other cell type. We report here a detailed analysis of the proximal regulatory region of the TTR gene, which has uncovered two new DNA-binding factors that are present mainly (or only) in hepatocytes. One of these new factors, hepatocyte nuclear factor 3 (HNF-3), binds to two sites that are crucial in TTR expression as well as to two additional sites in the alpha 1-AT proximal enhancer region. The second new factor, HNF-4, binds to two sites in TTR that are required for gene activity. We had previously identified binding sites for another hepatocyte-enriched DNA-binding protein (C/EBP or a relative thereof), and additional promoter-proximal sites for that protein in both TTR and alpha 1-AT are also reported here. From these results it seems clear that cell-specific expression is not simply the result of a single cell-specific factor for each gene but the result of a combination of such factors. The variation and distribution of such factors among different cell types could be an important basis for the coordinate expression of the TTR and alpha 1-AT genes in the liver or the discordant transcriptional activation of these genes in a few other cell types. The identification of such cell-enriched factors is a necessary prelude to understanding the basis for cell specificity.
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44
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Araki H, Oshima Y. An autonomously replicating sequence of pSRI plasmid is effective in two yeast species, Zygosaccharomyces rouxii and Saccharomyces cerevisiae. J Mol Biol 1989; 207:757-69. [PMID: 2668540 DOI: 10.1016/0022-2836(89)90242-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The autonomously replicating sequences (ARSs) of pSR1, a cryptic circular DNA plasmid detected in a strain of Zygosaccharomyces rouxii, were delimited by subcloning and deletion analysis and by the isolation of nucleotide substitution mutations. A 30 base-pair (bp) sequence from inverted repeat 1 (IR1) and presumably the same region from IR2 of pSR1 functions as an ARS in the native host, Z. rouxii, and in a heterologous host, Saccharomyces cerevisiae. Thus, pSR1 has two ARSs per molecule, either of which is sufficient for replication of the plasmid molecule in both hosts. These hosts, however, respond differently to nucleotide substitutions in the 30 bp sequence, suggesting that the sequences required for ARS function in the two organisms are not exactly the same. In addition, a 137 bp sequence that overlaps the 30 bp sequence by 11 bp also functions as an ARS in Z. rouxii but not in S. cerevisiae. However, this 137 bp sequence enhances the stability of plasmids carrying the pSR1 ARS in S. cerevisiae. The 30 bp and 137 bp sequences each contain a single copy of the 11 bp ARS consensus sequence, which is essential for ARS function in S. cerevisiae. Small insertions between the 11 bp overlapping region and the 11 bp ARS consensus sequence showed that a proper distance between these two 11 bp sequences is essential for the ARS function of the 30 bp sequence. Point mutations that inactivate ARS function show that the ARS consensus sequence, as well as a short A:T segment in the overlapping sequence, is required for the ARS function of the 30 bp sequence.
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Affiliation(s)
- H Araki
- Department of Fermentation Technology, Faculty of Engineering, Osaka University, Japan
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45
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Adrian T, Best B, Hierholzer JC, Wigand R. Molecular epidemiology and restriction site mapping of adenovirus type 3 genome types. J Clin Microbiol 1989; 27:1329-34. [PMID: 2546977 PMCID: PMC267552 DOI: 10.1128/jcm.27.6.1329-1334.1989] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
One hundred thirty-eight strains of adenovirus type 3 isolated from patients in the United States, West Germany, and other regions between 1961 and 1984 were analyzed with six restriction endonucleases; 18 genome types were found. BglII was the most discriminative enzyme. Mapping of altered restriction sites was also performed for all six enzymes. The genome types D1 (like the prototype) and D3 prevailed among 45 and 47 strains, respectively. All genome types could be divided into two groups related to D1 or D3. Several clusters of infections by strains with the same genome type were observed. Only hints of differences were found in the pathogenicities of individual genome types. D1 strains were present in the United States and in Europe; group D3 prevailed almost exclusively in the United States.
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Affiliation(s)
- T Adrian
- Abteilung für Virologie, Universitätskliniken, Homburg, Saar, Federal Republic of Germany
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46
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Park SS, Wong SL, Wang LF, Doi RH. Bacillus subtilis subtilisin gene (aprE) is expressed from a sigma A (sigma 43) promoter in vitro and in vivo. J Bacteriol 1989; 171:2657-65. [PMID: 2496113 PMCID: PMC209949 DOI: 10.1128/jb.171.5.2657-2665.1989] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In vitro studies demonstrated that the Bacillus subtilis subtilisin gene (aprE) could be transcribed by RNA polymerase holoenzyme reconstituted from core and sigma A factor obtained from vegetative cells. Upstream deletions (from -45) reduced the amount of transcription from the promoter. A deletion downstream of the promoter that overlapped a putative downstream minor promoter did not affect transcription from the sigma A promoter, which indicated that the putative downstream promoter is not utilized in vivo. S1 nuclease mapping studies showed that there was a low level of transcription from the subtilisin promoter during the growth phase and that the site of transcription initiation was the same during log and stationary phases. We conclude from these findings that there is only one promoter for the subtilisin gene and that it can be transcribed by the sigma A form of RNA polymerase in vitro.
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Affiliation(s)
- S S Park
- Department of Biochemistry and Biophysics, University of California, Davis 95616
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47
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Costa RH, Grayson DR, Darnell JE. Multiple hepatocyte-enriched nuclear factors function in the regulation of transthyretin and alpha 1-antitrypsin genes. Mol Cell Biol 1989; 9:1415-25. [PMID: 2786140 PMCID: PMC362558 DOI: 10.1128/mcb.9.4.1415-1425.1989] [Citation(s) in RCA: 203] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Transthyretin (TTR) and alpha 1-antitrypsin (alpha 1-AT) are expressed at high levels in the liver and also in at least one other cell type. We report here a detailed analysis of the proximal regulatory region of the TTR gene, which has uncovered two new DNA-binding factors that are present mainly (or only) in hepatocytes. One of these new factors, hepatocyte nuclear factor 3 (HNF-3), binds to two sites that are crucial in TTR expression as well as to two additional sites in the alpha 1-AT proximal enhancer region. The second new factor, HNF-4, binds to two sites in TTR that are required for gene activity. We had previously identified binding sites for another hepatocyte-enriched DNA-binding protein (C/EBP or a relative thereof), and additional promoter-proximal sites for that protein in both TTR and alpha 1-AT are also reported here. From these results it seems clear that cell-specific expression is not simply the result of a single cell-specific factor for each gene but the result of a combination of such factors. The variation and distribution of such factors among different cell types could be an important basis for the coordinate expression of the TTR and alpha 1-AT genes in the liver or the discordant transcriptional activation of these genes in a few other cell types. The identification of such cell-enriched factors is a necessary prelude to understanding the basis for cell specificity.
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Affiliation(s)
- R H Costa
- Rockefeller University, New York, New York 10021
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48
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Tseng BY, Prussak CE. Sequence and structural requirements for primase initiation in the SV40 origin of replication. Nucleic Acids Res 1989; 17:1953-63. [PMID: 2538800 PMCID: PMC317535 DOI: 10.1093/nar/17.5.1953] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Primase synthesizes decaribonucleotides for priming of lagging and possibly leading strand synthesis at a replication fork. The sites of initiation by purified mouse primase were shown to be highly specific within the SV40 origin of replication. This study further examines the role of the 27-bp inverted repeat in the origin for initiation. A site is observed on the L-strand template at nucleotide position (np) 22 positioned a similar distance from the 27-bp inverted repeat as sites previously reported on the E-strand. The initiations adjacent to the 27-bp repeat have a higher Km for rATP than other sites. A deletion within the inverted repeat eliminated initiation at sites proximal to the hairpin on both E and L strands but had no effect at more distant sites. A deletion mutant which left the inverted repeat intact but deleted the initiation sites at np 5210-5220 on the E-strand was not active as a template for proximal sites. These results indicate that primase has two modes of recognition, one that requires the SV40 inverted repeat structure and a specific sequence and another that requires sequence alone. Additional regions of the SV40 genome have also been examined and of approximately 2000 nucleotides of single stranded template examined, only one additional site was observed at np 2412 on the E-strand. This indicates that primase initiations are highly specific for the SV40 origin and their potential functional role is discussed.
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Affiliation(s)
- B Y Tseng
- Eukaryotic Regulatory Biology Program, School of Medicine, University of California, San Diego, La Jolla 92093
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49
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Adrian T, Becker M, Hierholzer JC, Wigand R. Molecular epidemiology and restriction site mapping of adenovirus 7 genome types. Arch Virol 1989; 106:73-84. [PMID: 2548461 DOI: 10.1007/bf01311039] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
From the United States, the Federal Republic of Germany, and other regions, 168 strains of AV7, isolated between 1961 and 1985, were analyzed by six restriction endonucleases and nine genome types were identified. The enzymes BamHI and HindIII were most discriminative. The genome type D5 (or 7b) predominated with 120 isolates since 1970 in both countries. Strains of D2 (7a) and D4 (7c) were isolated for a limited time, D3 for an extended time period. Several clusters of infections with the same genome type were found. Differences in pathogenicity could not be derived from our data. On the basis of restriction site mapping, most other genome types were similar to D5, one to D2 and one to the prototype (D1). The genomic relation between AV7 and AV3 is discussed and shown by a dendrogram.
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Affiliation(s)
- T Adrian
- Institut für Virologie und Seuchenhygiene, Medizinische Hochschule, Hannover, Federal Republic of Germany
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50
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Sex-specific control of Drosophila melanogaster yolk protein 1 gene expression is limited to transcription. Mol Cell Biol 1989. [PMID: 3145403 DOI: 10.1128/mcb.8.11.4756] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The sex of Drosophila melanogaster is determined by a hierarchy of genes. The ultimate targets of this regulatory hierarchy are the genes encoding terminal differentiation products of one sex. For one of the best-characterized target genes, that encoding female-specific yolk protein 1 (YP1), sex-specific transcriptional controls have been clearly demonstrated. In addition, sex-specific posttranscriptional controls were suggested from experiments in which YP1 RNA was induced in males with hormones. To determine whether males can efficiently process and translate a transcript which is normally found only in females, we used a non-sex-specific promoter, the hsp70 gene promoter, to drive YP1 gene transcription in germ line transformed males. The efficiency of expression of the YP1 gene at levels of RNA splicing, translation, and protein secretion in these males was compared with that in wild-type females. These experiments show that there are no sex-specific posttranscriptional controls operating to limit the production of secreted YP1 in males. Promoters containing different numbers of heat shock elements were tested for their ability to drive YP1 gene transcription in males. These results show that incompatibility between the hsp70 gene heat shock elements and the YP1 gene promoter can be overcome by increasing the amount of hsp70 gene sequence up or downstream of the TATA box. In the course of this study, two vectors useful for placing genes under heat shock regulation were constructed. One of these vectors is designed so that the heat-induced transcript produced is the "authentic" primary transcript; it should be useful for studies of posttranscriptional regulation.
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