Transient Receptor Potential (TRP) ion channels in human health and disease
Lysosomes are important cell organelles involved in the breakdown of membrane proteins and other molecules. These intracellular vesicles have been implicated in many neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease and Mucolipidosis type IV. The lysosomal membrane contains a diverse number of receptor and ion channel proteins that mediate its normal function. Some of these proteins are also involved in protein trafficking through processes known as endocytosis and exocytosis. It is thus not surprising that dysfunction of these proteins result in human pathological conditions.
The Cuajungco lab is interested in the role that specific lysosomal membrane proteins and ion channels play during normal and pathological states. Our investigations involve collaborations from various disciplines within CSUF and other institutions. We use both prokaryotic and eukaryotic cell culture models, as well as molecular and cellular biology methods to accomplish our research goals. One of our projects use membrane-based yeast two-hybrid genetic screens to identify protein-protein interactors for TRP channels found in lysosomes. Subsequently, we aim to characterize the functional significance of identified membrane protein interactors for the TRP channels using biochemical and microscopy techniques. Another aspect of our research is to study the relationships between lysosomes and metal transport or storage using fluorescence microscopy and spectroscopy. Finally, we use RNA interference to target lysosomal TRP channels, and analyze gene expression of certain lysosome-associated proteins to uncover hidden signaling pathways involved in cellular endocytosis and exocytosis events.
Selected publications (Click for full list)
Samie M.A., Grimm C., Evans J.E., Curcio-Morelli, C., Heller, S., Slaugenhaupt, S.A. and Cuajungco, M.P. The tissue-specific expression of TRPML2 (MCOLN-2) gene is influenced by the presence of TRPML1. Pflügers Archiv – European Journal of Physiology, in press
Cuajungco, M.P. and Samie, M.A. The varitint-waddler mouse phenotypes and the TRPML3 mutation: cause and consequence. Pflügers Archiv – European Journal of Physiology 2008 457: 463-4734
D`hoedt, D., Owsianik, G., Prenen, J., Cuajungco, M.P., Grimm, C., Heller, S., Voets, T. and Nilius, B. Stimulus-specific Modulation of the Cation Channel TRPV4 by PACSIN 3. Journal of Biological Chemistry 2008 283 6272-6280
Grimm, C., Cuajungco, M.P., van Aken, A.F.J., Schnee, M., Jors, S., Kros, C.J., Ricci, A.J. and Heller, S. A helix-breaking mutation in TRPML3 leads to constitutive activity underlying deafness in the varitint-waddler mouse. Proceedings of the National Academy of Sciences USA 2007 104 19583-19588
Cuajungco, M.P., Grimm, C., Oshima, K., D`Hoedt, D., Mensenkamp, A. R., Bindels, R. J., Nilius, B., Plomann, M., and Heller, S. PACSINs bind to the TRPV4 cation channel: PACSIN 3 modulates the subcellular localization of TRPV4. Journal of Biological Chemistry 2006 281 18753-18762