juan franko - Academia.edu (original) (raw)

Papers by juan franko

Research paper thumbnail of FIA-related papers and monographs which appeared since 1984 have been compiled in this bibliography. All papers are numbered in series and shown with the titles in English

Research paper thumbnail of Arabidopsis UEV1D Promotes Lysine63Linked Polyubiquitination and Is Involved in DNA Damage Response

Plant Cell, 2008

DNA damage tolerance (DDT) in budding yeast requires Lys-63-linked polyubiquitination of the prol... more DNA damage tolerance (DDT) in budding yeast requires Lys-63-linked polyubiquitination of the proliferating cell nuclear antigen. The ubiquitin-conjugating enzyme Ubc13 and the Ubc enzyme variant (Uev) methyl methanesulfonate2 (Mms2) are required for this process. Mms2 homologs have been found in all eukaryotic genomes examined; however, their roles in multicellular eukaryotes have not been elucidated. We report the isolation and characterization of four UEV1 genes from Arabidopsis thaliana. All four Uev1 proteins can form a stable complex with At Ubc13 or with Ubc13 from yeast or human and can promote Ubc13-mediated Lys-63 polyubiquitination. All four Uev1 proteins can replace yeast MMS2 DDT functions in vivo. Although these genes are ubiquitously expressed in most tissues, UEV1D appears to express at a much higher level in germinating seeds and in pollen. We obtained and characterized two uev1d null mutant T-DNA insertion lines. Compared with wild-type plants, seeds from uev1d null plants germinated poorly when treated with a DNA-damaging agent. Those that germinated grew slower, and the majority ceased growth within 2 weeks. Pollen from uev1d plants also displayed a moderate but significant decrease in germination in the presence of DNA damage. This report links Ubc13-Uev with functions in DNA damage response in Arabidopsis.

Research paper thumbnail of 90th Annual Convention Poster Presentations and Abstracts

Diseases of The Colon & Rectum, 1991

Abstracts appear in the order of presentation. Their number corresponds to the title listed in th... more Abstracts appear in the order of presentation. Their number corresponds to the title listed in the scientific program.

Research paper thumbnail of Frustration of magnetic interactions in heavy fermion compounds: CeNi2-xSn2 and other 1:2:2 compounds

Physica B-condensed Matter, 1994

The crystallographic structure of CeNi 2_xsn2 compound is reinvestigated. Two phases occur depend... more The crystallographic structure of CeNi 2_xsn2 compound is reinvestigated. Two phases occur depending on preparation, the first being tetragonal, the other monoclinic with some Ni deficiency. The antiferromagnetic structure below T~ = 2.1 K is shown to be highly frustrated. The measured ordered moment reaches 0.90#a at 1.5 K, 78% of the value calculated for a crystal field ionic model. This reduction is in agreement with that inferred from the analysis of specific heat data. We discuss the occurrence of magnetic frustration, its incidence on long range order and on the anisotropy of the magnetic correlation length in related systems.

Research paper thumbnail of 93rd annual convention podium and poster abstracts

Diseases of The Colon & Rectum, 1994

CM Davis, SA Strong .............. Cleveland, OH Proctectomy for severe perianal Crohn&am... more CM Davis, SA Strong .............. Cleveland, OH Proctectomy for severe perianal Crohn's disease (CD) is associated with a significant risk (15-70 percent) for an unhealed perineal wound (UPW) which is defined as more than 6 months delay in complete healing. While ...

Research paper thumbnail of Definition of an Efficient Transmission System Using Cooperative Games Theory

IEEE Transactions on Power Systems, 2006

Under a context of transmission open access, a methodology to define a common transmission trunk ... more Under a context of transmission open access, a methodology to define a common transmission trunk system using economic and technical criteria is proposed. A transmission trunk system is defined as a unique and common system constituted by electrical lines and substations that are economically efficient and necessary to allow the development of an electrical market and the supply of demand in the respective electrical system at a minimum cost and in an efficient manner. The principles of cooperation and interaction between agents that are the base for the cooperative games theory are used. Simple games and the Shapley Value approach are used. The proposal responds to the need to identify a common main system, common to supply and demand agents, needed in system open access schemes in electricity markets.

Research paper thumbnail of Contributory presentations/posters

Journal of Biosciences, 1999

Research paper thumbnail of Abstracts of the 6th Canadian Neuro-Oncology Meeting May 18–21, 1994 Lake Louise, Alberta

Journal of Neuro-oncology, 1994

fibrillary acidic protein (GFAP) is an intermediate filament specifically expressed In gUM cells ... more fibrillary acidic protein (GFAP) is an intermediate filament specifically expressed In gUM cells which conlributes to and malnlains the stability of the astrocyte's cytoskeleton. We have previously observed that GFAP expression is reduced in rnalignant glial tmnors, and that the up-regulation of GFAP expression affects glial cell proliferation and tumorigenicity (Cancer Res. 53:3624, 1993). To determine how the transcription of the GFAP is repressed in malignant glial tumors, we looked for genomle rearrangements of the GFAP gene by Southern analysis, but none was found. However, we have shown for the first time that the GFAP gene was hyper-methylated in five GFAP negative glioma cells. This hyper-methylalion was also detected in other GFAP negative non-glial cells. Both hyper-and hypo-methylation of DNA have been shown in a variety of tumor types to be important [actors affecting gene transcription. This methylation-mediated repression of transcription is thought to be a candidate mechanism for the decreased expression of several tumor suppressor genes, and may also be one mechanism by which there is loss of GFAP gene expression in malignant gliomas (Supported by NCI Canada).

Research paper thumbnail of Links ayuda codigos

Research paper thumbnail of FIA-related papers and monographs which appeared since 1984 have been compiled in this bibliography. All papers are numbered in series and shown with the titles in English

Research paper thumbnail of Arabidopsis UEV1D Promotes Lysine63Linked Polyubiquitination and Is Involved in DNA Damage Response

Plant Cell, 2008

DNA damage tolerance (DDT) in budding yeast requires Lys-63-linked polyubiquitination of the prol... more DNA damage tolerance (DDT) in budding yeast requires Lys-63-linked polyubiquitination of the proliferating cell nuclear antigen. The ubiquitin-conjugating enzyme Ubc13 and the Ubc enzyme variant (Uev) methyl methanesulfonate2 (Mms2) are required for this process. Mms2 homologs have been found in all eukaryotic genomes examined; however, their roles in multicellular eukaryotes have not been elucidated. We report the isolation and characterization of four UEV1 genes from Arabidopsis thaliana. All four Uev1 proteins can form a stable complex with At Ubc13 or with Ubc13 from yeast or human and can promote Ubc13-mediated Lys-63 polyubiquitination. All four Uev1 proteins can replace yeast MMS2 DDT functions in vivo. Although these genes are ubiquitously expressed in most tissues, UEV1D appears to express at a much higher level in germinating seeds and in pollen. We obtained and characterized two uev1d null mutant T-DNA insertion lines. Compared with wild-type plants, seeds from uev1d null plants germinated poorly when treated with a DNA-damaging agent. Those that germinated grew slower, and the majority ceased growth within 2 weeks. Pollen from uev1d plants also displayed a moderate but significant decrease in germination in the presence of DNA damage. This report links Ubc13-Uev with functions in DNA damage response in Arabidopsis.

Research paper thumbnail of 90th Annual Convention Poster Presentations and Abstracts

Diseases of The Colon & Rectum, 1991

Abstracts appear in the order of presentation. Their number corresponds to the title listed in th... more Abstracts appear in the order of presentation. Their number corresponds to the title listed in the scientific program.

Research paper thumbnail of Frustration of magnetic interactions in heavy fermion compounds: CeNi2-xSn2 and other 1:2:2 compounds

Physica B-condensed Matter, 1994

The crystallographic structure of CeNi 2_xsn2 compound is reinvestigated. Two phases occur depend... more The crystallographic structure of CeNi 2_xsn2 compound is reinvestigated. Two phases occur depending on preparation, the first being tetragonal, the other monoclinic with some Ni deficiency. The antiferromagnetic structure below T~ = 2.1 K is shown to be highly frustrated. The measured ordered moment reaches 0.90#a at 1.5 K, 78% of the value calculated for a crystal field ionic model. This reduction is in agreement with that inferred from the analysis of specific heat data. We discuss the occurrence of magnetic frustration, its incidence on long range order and on the anisotropy of the magnetic correlation length in related systems.

Research paper thumbnail of 93rd annual convention podium and poster abstracts

Diseases of The Colon & Rectum, 1994

CM Davis, SA Strong .............. Cleveland, OH Proctectomy for severe perianal Crohn&am... more CM Davis, SA Strong .............. Cleveland, OH Proctectomy for severe perianal Crohn's disease (CD) is associated with a significant risk (15-70 percent) for an unhealed perineal wound (UPW) which is defined as more than 6 months delay in complete healing. While ...

Research paper thumbnail of Definition of an Efficient Transmission System Using Cooperative Games Theory

IEEE Transactions on Power Systems, 2006

Under a context of transmission open access, a methodology to define a common transmission trunk ... more Under a context of transmission open access, a methodology to define a common transmission trunk system using economic and technical criteria is proposed. A transmission trunk system is defined as a unique and common system constituted by electrical lines and substations that are economically efficient and necessary to allow the development of an electrical market and the supply of demand in the respective electrical system at a minimum cost and in an efficient manner. The principles of cooperation and interaction between agents that are the base for the cooperative games theory are used. Simple games and the Shapley Value approach are used. The proposal responds to the need to identify a common main system, common to supply and demand agents, needed in system open access schemes in electricity markets.

Research paper thumbnail of Contributory presentations/posters

Journal of Biosciences, 1999

Research paper thumbnail of Abstracts of the 6th Canadian Neuro-Oncology Meeting May 18–21, 1994 Lake Louise, Alberta

Journal of Neuro-oncology, 1994

fibrillary acidic protein (GFAP) is an intermediate filament specifically expressed In gUM cells ... more fibrillary acidic protein (GFAP) is an intermediate filament specifically expressed In gUM cells which conlributes to and malnlains the stability of the astrocyte's cytoskeleton. We have previously observed that GFAP expression is reduced in rnalignant glial tmnors, and that the up-regulation of GFAP expression affects glial cell proliferation and tumorigenicity (Cancer Res. 53:3624, 1993). To determine how the transcription of the GFAP is repressed in malignant glial tumors, we looked for genomle rearrangements of the GFAP gene by Southern analysis, but none was found. However, we have shown for the first time that the GFAP gene was hyper-methylated in five GFAP negative glioma cells. This hyper-methylalion was also detected in other GFAP negative non-glial cells. Both hyper-and hypo-methylation of DNA have been shown in a variety of tumor types to be important [actors affecting gene transcription. This methylation-mediated repression of transcription is thought to be a candidate mechanism for the decreased expression of several tumor suppressor genes, and may also be one mechanism by which there is loss of GFAP gene expression in malignant gliomas (Supported by NCI Canada).

Research paper thumbnail of Links ayuda codigos