Uncovering the role of SPCA2 in the SK3 channel complex
Sprache der Bezeichnung:
Englisch
Original Kurzfassung:
Ca2+ ions govern a wide range of essential cellular functions. A defect in a single Ca2+ signaling protein can lead to an abnormal cellular Ca2+ milieu and cause devastating long-term consequences such as carcinogenesis. We are particularly interested the interplay of Ca2+-permeable and Ca2+-activated ion channels as it can promote cancer development. In this project, we focus on the co-regulation of the small conductance K+ channel, SK3, a Ca2+ ion channel, Orai1, and a Ca2+-ATPase in the Golgi secretory pathway, SPCA2. We aim to study the role of SPCA2 in regulating the interplay of SK3 and Orai1 channels. Although there is clear evidence for a co-regulation of SK3 and Orai1, the molecular linkers for this interplay are still poorly understood. We propose that SPCA2 represents another suitable candidate to regulate the SK3 signaling complex. We will study for the first time the functional impact of SPCA2 on the SK3 channel alone as well as on the SK3-Orai1 complex and uncover important molecular determinants thereof using a combined approach of functional, fluorescence microscopy, and biochemical studies. In addition to the current knowledge based on the findings in breast cancer cells, we will expand our investigation to study the molecular interaction of this trio complex in melanoma and prostate cancer-derived cells. We expect to identify a direct molecular link that stabilizes the SK3-Orai1 complex. Identification of these targets (SK3, SPCA2, Orai1) and regulatory mechanisms and investigating their molecular interaction helps, in the long run, to establish strategies for therapeutic developments that directly interfere with the communication of SK3, SPCA2, and Orai1. Hence, our approach will not only allow for an in-depth understanding of a disease-relevant branch in Ca2+ signaling but can, in consequence, provide a fundamental basis for the examination of the trio-complex in primary cancer cells and cancer biopsies.