Joost completed his Ph.D. studying glial-neuronal interactions in Vanessa Auld's lab at the Univ. of British Columbia.  Joost started in the lab in August, 2005 and is working on several projects, including the identification of chemical suppressors of Huntingtin PolyQ-dependent toxicity, and the biochemical purification of postsynaptic Synaptotagmin 4-containing vesicles.

Junctions are junctions.  My background is in the study of Drosophila pleated septate junctions, which are highly speacialized structures that are necessary to form the blood-brain-barrier in flies.  In the Littleton lab, I have shifted my focus slightly to study another junction type: the neuronal synapse.  All cellular junctions are similar in that they are relatively stable structures that are rich in cell adhesion molecules and PDZ domain containing scaffold proteins.  Functionally, junctions are similar in that they are often sites of signal transduction and the targets of vesicular traffic.  This latter function is something that I am particularly interested in.  In the Littleton Lab, I am studying a vesicle protein called Synaptotagmin-4 (Syt-4).  Syt-4 is a member of the Synaptotagmin family of calcium binding proteins.  Syt-1 is the best studied member of this family and it localizes to vesicles in presynaptic nerve terminals where it functions to bring about vesicle fusion and the release of neurotransmitters into the synaptic cleft.  In contrast to Syt-1, Syt-4 is enriched in vesicles at postsynaptic terminals where it appears to be involved in retrograde signaling to the presynaptic membrane (Yoshihara et al., 2005).  I am using protein biochemistry and mass spectrometry to identify the constituents of Syt-4 vesicles.  

Publications:

Schulte, J., Charish, K., Que, J., Ravn, S., MacKinnon, C., and Auld, V.J.  (2006).  Gliotactin and Discs large form a protein complex at the tricellular junction of polarized epithelial cells in Drosophila.  In Press: J. Cell Science.

 Wu V.M., Schulte J, Hirschi A, Tepass U, Beitel GJ.  (2004).  Sinuous is a Drosophila claudin required for septate junction organization and epithelial tube size control.  J. Cell Biol.  164(2):313-23.

 Schulte, J., Tepass, U., and Auld, V.J. (2003).  Gliotactin, a novel marker of tricellular junctions, is necessary for septate junction development in Drosophila.  J Cell Biol. 161(5):991-1000

 Sepp, K.J., Schulte, J., Auld, V.J.  (2001).  Peripheral glia direct axon guidance across the CNS/PNS transition zone.  Dev Biol. 238(1):47-63.

Sepp, K.J., Schulte, J., Auld V.J.  (2000).  Developmental dynamics of peripheral glia in Drosophila melanogaster.  Glia. 30(2):122-33.

Joost completed his Ph.D. studying glial-neuronal interactions in Vanessa Auld's lab at the Univ. of British Columbia.  Joost started in the lab in August, 2005 and is working on several projects, including the identification of chemical suppressors of Huntingtin PolyQ-dependent toxicity, and the biochemical purification of postsynaptic Synaptotagmin 4-containing vesicles.

Junctions are junctions.  My background is in the study of Drosophila pleated septate junctions, which are highly speacialized structures that are necessary to form the blood-brain-barrier in flies.  In the Littleton lab, I have shifted my focus slightly to study another junction type: the neuronal synapse.  All cellular junctions are similar in that they are relatively stable structures that are rich in cell adhesion molecules and PDZ domain containing scaffold proteins.  Functionally, junctions are similar in that they are often sites of signal transduction and the targets of vesicular traffic.  This latter function is something that I am particularly interested in.  In the Littleton Lab, I am studying a vesicle protein called Synaptotagmin-4 (Syt-4).  Syt-4 is a member of the Synaptotagmin family of calcium binding proteins.  Syt-1 is the best studied member of this family and it localizes to vesicles in presynaptic nerve terminals where it functions to bring about vesicle fusion and the release of neurotransmitters into the synaptic cleft.  In contrast to Syt-1, Syt-4 is enriched in vesicles at postsynaptic terminals where it appears to be involved in retrograde signaling to the presynaptic membrane (Yoshihara et al., 2005).  I am using protein biochemistry and mass spectrometry to identify the constituents of Syt-4 vesicles.  

Publications:

Schulte, J., Charish, K., Que, J., Ravn, S., MacKinnon, C., and Auld, V.J.  (2006).  Gliotactin and Discs large form a protein complex at the tricellular junction of polarized epithelial cells in Drosophila.  In Press: J. Cell Science.

 Wu V.M., Schulte J, Hirschi A, Tepass U, Beitel GJ.  (2004).  Sinuous is a Drosophila claudin required for septate junction organization and epithelial tube size control.  J. Cell Biol.  164(2):313-23.

 Schulte, J., Tepass, U., and Auld, V.J. (2003).  Gliotactin, a novel marker of tricellular junctions, is necessary for septate junction development in Drosophila.  J Cell Biol. 161(5):991-1000

 Sepp, K.J., Schulte, J., Auld, V.J.  (2001).  Peripheral glia direct axon guidance across the CNS/PNS transition zone.  Dev Biol. 238(1):47-63.

Sepp, K.J., Schulte, J., Auld V.J.  (2000).  Developmental dynamics of peripheral glia in Drosophila melanogaster.  Glia. 30(2):122-33.