That's me with my most successful experiments!
(I am just the co-author, the group leader, Margot, is too busy tending the experiments to have her picture taken!)

 

Abstract:

LIGHT CALCIUM AND THE NUCLEAR PORE COMPLEX

Blue light is a primary signal controlling many aspects of plant growth and development.  Using plants transformed with the cDNA for the calcium-sensitive luminescent protein aequorin, we found that pulses of blue light induce transient elevation in the concentration of cytosolic calcium.  Red light failed to induce changes in calcium concentration even at intensities 100 times stronger than required by blue light.  Using plants expressing nuclear targeted aequorin (aequorin fused to nucleoplasmin), we found that neither red nor blue light had any effect on nuclear calcium concentration.  We found that the source for the cytoplasmic calcium increase is extracellular.  Experiments with the long hypocotyl hy-4 mutant expressing aequorin showed that the blue light receptor eliciting this signal is not the hy-4 gene product- CRY-1.  We hypothesise that light induced changes in calcium concentration around the nuclear pore may regulate the passage of transcription factors into and out of the nucleus, thus controlling gene expression.  In order to study the mechanisms by which blue light induced changes in cytosolic calcium concentrations can affect gene expression, we are currently producing plants expressing aequorin targeted to the nuclear pore.  Nup 57-aequorin fusion, nup 82-aequorin fusion, nup 49-aequorin and the localisation peptide of gp210 fused to aequorin (either at the C-terminal and or N-terminal, to measure calcium concentration both in the nuclear cysterna and inside the pore) are all being introduced into Arabidopsis plants.  Using an extremely sensitive modified aequorin luminescence detection system, we hope to be able to measure directly changes in calcium concentration in the nuclear pore immediate surrounding.

Fig. 1
q- [Ca2+] in response to 10' illumination.
x- [Ca2+] in response to 10' mock illumination

 
Succinct C.V.:

Born: 1962 in Israel

B.Sc.: Faculty of Agriculture, The Hebrew University, Rehovot Israel. 1984-1987

M.Sc.: Department of Genetics Weizmann Institute of Science, Rehovot Israel. 1987-1989
Under the supervision of Prof. Avri Ben Zee'v
Thesis title: Regulation of tropomyosin expression in differentiating granulosa cells in the ovary, in primary cultures and in established granulosa cell lines.

Ph.D.:  Department of Plant Genetics , Weizmann Institute of Science, Rehovot Israel. 1992-1996
Under the supervision of  Dr. Hillel Fromm.
Thesis title: Characterization of calmodulin-binding glutamate decarboxylase from petunia.

Currently a post doc at the  Institute of Cell and Molecular Biology (ICMB);  University of Edinburgh, Edinburgh, Scotland.
Under the supervision of Prof. Anthony J. Trewavas.
 

Publications:

Baum, G., Lev-Yadun, S., Fridmann, Y., Arazi, T., Katsnelson, H., Zik, M. and Fromm, H. (1996) Calmodulin binding to glutamate decarboxylase is required for regulation of glutamate and GABA metabolism and normal development in plants.  EMBO J.  15, 2988-2996
 
Snedden, WA., Koutsia, N., Baum, G. and Fromm, H. (1996) Activation of a recombinant Petunia glutamate decarboxylase by calcium/calmodulin or by a monoclonal antibody which recognizes the calmodulin-binding domain.  J. Biol. Chem. 271, 4148-4153   Download the Reprint (PDF)  (332K)

Arazi, T., Baum, G., Snedden, WA., Shelp, BJ. and Fromm, H. (1995) Molecular and biochemical analysis of calmodulin interactions with the calmodulin-binding domain of plant glutamate decarboxylase.  Plant Physiol.  108, 551-561

Chen, Y., Baum, G. and Fromm, H. (1994) The 58-Kilodalton calmodulin-binding glutamate decarboxylase is a ubiquitous protein in Petunia organs and its expression is developmentally regulated. Plant Physiol.  106, 1381-1387

Baum, G., Chen, Y., Arazi, T., Takatsuji, H. and Fromm, H. (1993) A plant glutamate decarboxylase containing a calmodulin binding domain.  J. Biol. Chem. 268, 19610-19617

Baum, G., Suh, BS., Amsterdam, A. and Ben-Ze'ev, A. (1990) Regulation of tropomyosin expression in transformed granulosa cell lines with steroidogenic ability. Dev. Biol. 142, 115-128

Ben-Ze'ev, A., Rodriguez, JLF., Baum, G. and Gorodecki, B. (1990) Regulation of cell contacts, cell configuration and cytoskeletal gene expression in differentiating systems. In: Mechnisms of differentiation  (P. Fisher ed), CRC Press.

Amsterdam, A., Suh, BS., Himelock, S., Baum, G. and Ben-Ze'ev, G. (1990) Modulation of granulosa cell ultrastructure during differentiation: organization and expression of cytoskeletal elements. In: Ultrastructure of the ovary (P. M. Motta ed), Martinus Nijhoff.

Ben-Ze'ev, A., Baum, G. and Amsterdam, A. (1989) Regulation of tropomyosin expression in the maturing ovary and in primary granulosa cell cultures. Dev. Biol., 135, 191-201