Laboratory of Synaptogenesis

Head: Tomasz Prószyński

Staff: Paweł NIEWIADOMSKI, Magda CHOJNACKA, Kasia ROJEK, Krzysztof BERNADZKI

Research profile:

Because of its simplicity, size and accessibility, the neuro- muscular junction (NMJ) serves as a useful model to study the biology of synapses. Similar to synapses in the CNS, NMJs undergo postnatal developmental changes. At NMJs simple assemblies of synaptic machinery rearrange into morphologically complex structures. Abnormalities in the development of NMJs have been observed in numerous disorders; however, the machinery responsible for synaptic remodeling is widely unknown. Our laboratory will use multidisciplinary approaches to elucidate mechanisms that orchestrate maturation of NMJs. We will study in detail the function of candidate postsynaptic organizers, search for novel key regulators and explore the possibility that podosomes, actin-rich, dynamic, adhesive organelles are involved in this process. In parallel, we will investigate whether the molecular machinery responsible for NMJ remodeling can also function during the development or remodeling of synapses in the brain

Methods:

• generation of conditional knockout mice
• cell culture, including neurons and myotubes
• immunocyto/histochemistry
• confocal microscopy
• generation of viral vectors
• biochemistry: protein complex purification, co-IP, Western blot
• mass spectrometry

Current research activities:

• studying involvement of Amotl2 and LL5B proteins in the remodeling of NMJs
• identification of novel key proteins orchestrating development of NMJs
• investigating the involvement of podosomes in remodeling of postsynaptic machinery
• examining the potential function of NMJ-remodeling pro teins at synapses in the CNS

Selected publications:

Prószyński T.J., Sanes J.R. (2013) Amotl2 interacts with LL5β, localizes to podosomes and regulates postsynaptic diff erentiation. Journal of Cell Science, doi:10.1242/jcs.121327.

Prószyński T.J., Gingras J., Valdez G., Krzewski K., Sanes J.R. (2009) Podosomes are present in a postsynaptic apparatus and participate in its maturation. Proceedings of the National Academy of Sciences USA, 106: 18373-18378.

Klemm R.W., Ejsing C.S., Surma M.A., Kaiser H.J., Gerl M.J., Sampaio J.L., de Robillard Q., Ferguson C., Prószyński T.J., Shevchenko A., Simons K. (2009) Segregation of sphingolipids and sterols during formation of secretory vesicles at the trans-Golgi network. Journal of Cell Biology, 185: 601-612.

Prószyński T.J., Klemm R.W., Bagnat M., Gaus K., Simons K. (2006) Plasma membrane polarization during mating in yeast cells. Journal of Cell Biology, 173: 861-866.

Prószyński T.J., Klemm R.W., Gravert M., Hsu P.P., Gloor Y., Wagner J., Kozak K., Grabner H., Walzer K., Bagnat M., Simons K., Walch-Solimena Ch. (2005) A genome-wide visual screen reveals a role for sphingolipids and ergosterol in cell surface delivery in yeast. Proceedings of the National Academy of Sciences USA, 102: 17981-17986.