Expression of heat shock protein 83 in Leishmania is regulated post-transcriptionally

Argaman, Miriam; Aly, Radi; Shapira, Michael Y.

doi:10.1016/0166-6851(94)90138-4

Cited by 91 publications

(74 citation statements)

References 32 publications

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“…The 427 array results, in contrast, mainly gave results only slightly greater than 1, and Northern blot analysis with 427 RNA also showed less than 1.5-fold regulation ( [27] and Robles, ZMBH, unpublished results). Notably, HSP83 RNA is expressed at higher levels in Leishmania promastigotes than amastigotes [28,29]. The only other gene with a 927-strain-specific signal was Tb07.27M11.780, which encodes an importin-like protein.…”

Section: Genes Showing Reproducible Regulationmentioning

confidence: 99%

The transcriptomes of Trypanosoma brucei Lister 427 and TREU927 bloodstream and procyclic trypomastigotes

Brems

Guilbride

Gundlesdodjir-Planck

et al. 2005

Molecular and Biochemical Parasitology

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We describe developmentally regulated genes in two strains of Trypanosoma brucei: the monomorphic strain Lister 427 and the pleomorphic strain TREU927. Expression patterns were obtained using an array of 24,567 genomic fragments. Probes were prepared from bloodstream-form or procyclic-form trypanosomes. Fourteen procyclic-specific and 77 bloodstream-specific signals were obtained from sequences matching variant surface glycoprotein or associated genes, and a further 17 regulated sequences were repetitive or transposable-element-related. Two hundred and eighty-six regulated spots corresponded to mRNAs from other protein-coding genes; these spots represent 191 different proteins. Regulation of 113 different genes (79 from procyclic forms, 34 from bloodstream-forms) was supported by at least two independent experiments or criteria; of these, about 60 were novel. Only two genes -encoding HSP83 and an importin-related protein -appeared to be regulated in the TREU927 strain only. Our results confirmed previous estimates that 2% of trypanosome genes show developmental regulation at the mRNA level.

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Section: Genes Showing Reproducible Regulationmentioning

confidence: 99%

The transcriptomes of Trypanosoma brucei Lister 427 and TREU927 bloodstream and procyclic trypomastigotes

Brems

Guilbride

Gundlesdodjir-Planck

et al. 2005

Molecular and Biochemical Parasitology

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“…has simplified several stage-specific genes characterizations, including heat shock proteins (HSP83 and HSP100), histone H1, cysteine proteinase, the A2 gene family, the LmcDNA gene family, the SL gene, and the gene encoding for a Ca 2ϩ -ATPase. [1][2][3][4][5]11,[15][16][17]19,20,24,26,27 Differential expression of the Ca 2ϩ -ATPase gene has also been involved with amastigote virulence and their ability to survive inside macrophages. The Ca 2ϩ -ATPase gene was selected as a molecular marker to characterize the axenic amastigotes.…”

Section: Discussionmentioning

confidence: 99%

“…Several amastigote-specific genes have been described in different Leishmania species, including hsp83, hsp100, histone H1, cpb cysteine proteinase, the A2 gene family, the LmcDNA16 gene family, the spliced leader RNA gene, and the Ca 2ϩ -ATPase gene. [1][2][3][4][5][15][16][17][18][19][20][21][22] Amastigote isolation, from either lesions or infected macrophages, usually produces low parasite numbers, contaminated by host components. 23,24 Axenic cultures have been obtained from several Leishmania species through changes in temperature and pH.…”

Section: Introductionmentioning

confidence: 99%

Cultivation and characterization of stable Leishmania guyanensis complex axenic amastigotes derived from infected U937 cells.

Puentes¹,

Díaz²,

Hoya³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

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Abstract. The study of the differential regulation of several genes, in both Leishmania parasite life cycle forms, has been simplified by the development of in vitro axenic amastigote culture. Different reports have described extracellular amastigote production and maintenance from several Leishmania spp. A general approach to induce amastigote-like transformation includes progressive pH and temperature changes. Production of axenic amastigotes in continuous cultures using amastigotes recovered from macrophages is described in this report. Leishmania (Viannia) panamensis (M/HOM/PA/71/LS94) and Leishmania (V). guyanensis (M/HOM/BR/75/M4147) intracellular amastigotes were recovered from the human macrophage-like U937 cell line previously infected with promastigotes. The parasites were immediately adapted for growth and kept as axenic amastigotes at 34ЊC and acidic pH. These organisms were able to infect macrophage cell lines, maintain amastigote morphologic features, and express stage-specific transcripts. The relevance of axenic amastigotes in characterizing virulence factors in American leishmaniasis is discussed.

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“…En los tripanosomátidos, la estructura cap es donada por ME. I: intrón; cap: residuo de 7-metilguanosina; poli A: sitio para la poliadenilación en el extremo 3' del transcrito; RI: región intergénica; ME: miniexón la transcripción y la regulación postranscripcional, debido a que Leishmania (y otros miembros de la familia Trypanosomatidae) posee un genoma con características poco ortodoxas en su organización y expresión, en comparación con la mayoría de los eucariotes (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). En Leishmania y Trypanosoma muchos genes se encuentran agrupados en unidades de transcripción policistrónicas que hacen que cada transcrito primario sea un ARNm precursor policistrónico (8) (figura 1).…”

Section: Transfecciónunclassified

“…Sin embargo, en Leishmania no se ha identificado ningún promotor específico para Pol II y la transcripción de genes a partir de vectores tampoco requiere de este promotor (104)(105)(106)(107). Los genes tripanosomátidos carecen de intrones, pero existe una dependencia importante de la presencia de las regiones intergénicas para la expresión de genes, lo cual indica que éstas contienen las señales necesarias para la transcripción y la maduración del ARNm (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). Por ello, para la expresión transitoria de genes en Leishmania se usan vectores de expresión circulares que contengan la secuencia MANIPULACIÓN GENÉTICA EN LEISHMANIA de un gen reportero flanqueado por regiones intergénicas del parásito (figura 2a).…”

Section: Transfecciónunclassified

Manipulación genética y el estudio del parásito protozoario Leishmania.

Cortázar

Walker

2004

biomedica

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Durante los últimos 15 años se ha dado paso al entendimiento de muchos aspectos de la genómica funcional de Leishmania gracias a los avances en la metodología de transfección de ADN dentro de la célula de este protozoario, la eliminación y la complementación de genes por medio de recombinación homóloga y las estrategias para la selección de células transfectadas. Estos acercamientos tienen el potencial de brindar información sobre la expresión génica y la función de las proteínas en el contexto del parásito intacto. Dado que el genoma de Leishmania muestra una carencia acentuada de los factores conocidos de iniciación de la transcripción y que la expresión génica está regulada casi completamente a nivel postranscripcional (a través del empalme de los ARNm y los mecanismos que involucran el procesamiento diferencial de la región no traducida 3' del ARNm (3'UTR), la transfección génica representa una herramienta útil para la identificación y el análisis funcional de los genes de interés así como de los mecanismos que dirigen su regulación. El desarrollo de los sistemas de manipulación genética también ha abierto nuevos horizontes para la identificación de genes esenciales involucrados en la virulencia, la supervivencia intracelular y la resistencia a drogas de Leishmania, así como para la validación de proteínas específicas del parásito como nuevos blancos quimio e inmunoterapéuticos. En esta revisión presentamos los avances más recientes en el campo de la manipulación genética en Leishmania, los cuales permiten análisis estructurales, funcionales y de fenotipo, por medio de la eliminación y complementación génica a través de la transfección transitoria o permanente de genes en este parásito.Palabras clave: Leishmania, transfección de ADN, expresión génica, eliminación y complementación génica, genómica funcional. Genetic manipulation and the study of the protozoan parasite LeishmaniaDuring the last 15 years, many aspects of the functional genomics of Leishmania have been revealed due to advances in DNA transfection, gene disruption and complementation through homologous recombination, and efficient strategies for the selection of transfected cells. These strategies have provided information about gene expression and protein function in the context of the intact parasite. The genome of Leishmania shows a marked deficiency of known transcription initiation factors, and gene expression is regulated almost entirely at the posttranscriptional level through trans-splicing of mRNAs and novel control mechanisms involving differential processing of 3' -untranslated regions (3'-UTRs) of mRNAs. Therefore, gene transfection represents a useful tool for the identification and functional analysis of genes of interest as well as the mechanisms that direct their regulation. The development of genetic manipulation systems has provided opportunities for the study of genes involved in virulence, intracellular survival and drug resistance of Leishmania, as well as for the functional validation of specific parasite proteins as new ch...

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Expression of heat shock protein 83 in Leishmania is regulated post-transcriptionally

Cited by 91 publications

References 32 publications

The transcriptomes of Trypanosoma brucei Lister 427 and TREU927 bloodstream and procyclic trypomastigotes

The transcriptomes of Trypanosoma brucei Lister 427 and TREU927 bloodstream and procyclic trypomastigotes

Cultivation and characterization of stable Leishmania guyanensis complex axenic amastigotes derived from infected U937 cells.

Manipulación genética y el estudio del parásito protozoario Leishmania.

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