Joaquin Medina - Academia.edu (original) (raw)

Joaquin Medina

Uploads

Papers by Joaquin Medina

Research paper thumbnail of Genetic analysis reveals a complex regulatory network modulating CBF gene expression and Arabidopsis response to abiotic stress

Journal of Experimental Botany, 2011

Research paper thumbnail of Proteins Are Part of an Abscisic Acid – VIVIPAROUS 1 ( VP 1 ) Response Complex in the Em Promoter and Interact with VP 1 and EmBP 1

Protein–DNA complexes were formed when nuclear extracts from embryogenic rice suspension cultures... more Protein–DNA complexes were formed when nuclear extracts from embryogenic rice suspension cultures or maize embryos were incubated with an abscisic acid–VIVIPAROUS1 (VP1) response element (Em1a) from the Em promoter. Monoclonal antibodies generated to GF14, a 14-3-3 protein from plants, resulted in gel retardation of the Em1a–protein complexes. Antibodies generated to the C and N termini of GF14 detected protein isoforms in rice nuclear and cytoplasmic extracts, but no differences in distribution of the GF14 isoforms were recognized between the nucleus and cytoplasm or when abscisic acid–treated and untreated tissues were compared. When recombinant GF14 fusion proteins from rice were added to nuclear extracts, novel complexes were formed that required the dimerization domain of GF14. Chemical cross-linking showed that GF-14 interacted with the basic leucine zipper factor EmBP1, which binds specifically to Em1a, and with VP1, which transactivates Em through Em1a. GF14 proteins from ri...

Research paper thumbnail of Production of a cytotoxic proteoglycan using callus culture of saffron corms (Crocus sativus L.)

Journal of …, 1999

Saffron corms have been demonstrated to contain a proteoglycan that inhibits growth of human tumo... more Saffron corms have been demonstrated to contain a proteoglycan that inhibits growth of human tumor cells. In this study, we show strong evidence indicating that callus cultures of saffron corm also synthesize such glycoconjugate. This compound is cytotoxic against human cervical epithelioid carcinoma cells (IC 50 = 7 mg ml − 1), and consists of approximately 90% carbohydrate and 10% protein. In order to optimize the glycoconjugate purification to complete functional and therapeutic studies, we have designed an improved method consisting of anion-exchange chromatography and reversed-phase HPLC, which can be easily scaled-up.

Research paper thumbnail of Genetic analysis reveals a complex regulatory network modulating CBF gene expression and Arabidopsis response to abiotic stress

Journal of Experimental Botany, 2011

Research paper thumbnail of Proteins Are Part of an Abscisic Acid – VIVIPAROUS 1 ( VP 1 ) Response Complex in the Em Promoter and Interact with VP 1 and EmBP 1

Protein–DNA complexes were formed when nuclear extracts from embryogenic rice suspension cultures... more Protein–DNA complexes were formed when nuclear extracts from embryogenic rice suspension cultures or maize embryos were incubated with an abscisic acid–VIVIPAROUS1 (VP1) response element (Em1a) from the Em promoter. Monoclonal antibodies generated to GF14, a 14-3-3 protein from plants, resulted in gel retardation of the Em1a–protein complexes. Antibodies generated to the C and N termini of GF14 detected protein isoforms in rice nuclear and cytoplasmic extracts, but no differences in distribution of the GF14 isoforms were recognized between the nucleus and cytoplasm or when abscisic acid–treated and untreated tissues were compared. When recombinant GF14 fusion proteins from rice were added to nuclear extracts, novel complexes were formed that required the dimerization domain of GF14. Chemical cross-linking showed that GF-14 interacted with the basic leucine zipper factor EmBP1, which binds specifically to Em1a, and with VP1, which transactivates Em through Em1a. GF14 proteins from ri...

Research paper thumbnail of Production of a cytotoxic proteoglycan using callus culture of saffron corms (Crocus sativus L.)

Journal of …, 1999

Saffron corms have been demonstrated to contain a proteoglycan that inhibits growth of human tumo... more Saffron corms have been demonstrated to contain a proteoglycan that inhibits growth of human tumor cells. In this study, we show strong evidence indicating that callus cultures of saffron corm also synthesize such glycoconjugate. This compound is cytotoxic against human cervical epithelioid carcinoma cells (IC 50 = 7 mg ml − 1), and consists of approximately 90% carbohydrate and 10% protein. In order to optimize the glycoconjugate purification to complete functional and therapeutic studies, we have designed an improved method consisting of anion-exchange chromatography and reversed-phase HPLC, which can be easily scaled-up.

Log In