Characterization of receptor protein tyrosine phosphatase PTP69D in the giant fiber circuit

• Other Authors: Lee, LaTasha Hoskins (author)
• Format: Others
• Language: English
• Published: Florida Atlantic University
• Subjects: Drosophila melanogaster.; Protein-tyrosine phosphatase > Metabolism.; Protein-tyrosine kinase.; Protein kinases > Inhibitors.; Phosphoprotein phosphatases.; Transcription factors.; Cell receptors.; Cellular signal transduction.
• Online Access: http://purl.flvc.org/fau/fd/FA00004301; http://purl.flvc.org/fau/fd/FA00004301

PTP69D is a receptor protein tyrosine phosphatase (RPTP) with two intracellular catalytic domains (Cat1 and Cat2), which has been shown to play a role in axon outgrowth and guidance of embryonic motorneurons, as well as targeting of photoreceptor neurons in the visual system of Drosophila melanogaster. Here, we characterized the developmental role of PTP69D in the giant fiber (GF) neurons; two interneurons in the central nervous system (CNS) that control the escape response of the fly. In addition to guidance and targeting functions, our studies reveal an additional role for PTP69D in synaptic terminal growth in the CNS. We found that inhibition of phosphatase activity in catalytic domain (Cat1) proximal to the transmembrane domain did not affect axon guidance or targeting but resulted in stunted terminal growth of the GFs. Cell autonomous rescue and knockdown experiments demonstrated a function for PTP69D in the GFs, but not its postsynaptic target neurons. In addition,complementation studies and structure-function analyses revealed that for GF terminal growth, Cat1 function of PTP69D requires the immunoglobulin and the Cat2 domain but not the fibronectin type III repeats nor the membrane proximal region. In contrast, the fibronectin type III repeats, but not the immunoglobulin domains, were previously shown to be essential for axon targeting of photoreceptor neurons. Thus, our studies uncover a novel role for PTP69D in synaptic terminal growth in the CNS that is mechanistically distinct from its function during earlier developmental processes. === Includes bibliography. === Dissertation (Ph.D.)--Florida Atlantic University, 2014. === FAU Electronic Theses and Dissertations Collection