Nucleoside Diphosphate Kinase, a Source of GTP, Is Required for Dynamin-Dependent Synaptic Vesicle Recycling

Abstract

Nucleoside diphosphate kinase (NDK), an enzyme encoded by the Drosophila abnormal wing discs (awd) or human nm23 tumor suppressor genes, generates nucleoside triphosphates from respective diphosphates. We demonstrate that NDK regulates synaptic vesicle internalization at the stage where function of the dynamin GTPase is required. awd mutations lower the temperature at which behavioral paralysis, synaptic failure, and blocked membrane internalization occur at dynamin-deficient, shi(ts), mutant nerve terminals. Hypomorphic awd alleles display shi(ts)-like defects. NDK is present at synapses and its enzymatic activity is essential for normal presynaptic function. We suggest a model in which dynamin activity in nerve terminals is highly dependent on NDK-mediated supply of GTP. This connection between NDK and membrane internalization further strengthens an emerging hypothesis that endocytosis, probably of activated growth factor receptors, is an important tumor suppressor activity in vivo.

Progress on Nme (NDP kinase/Nm23/Awd) gene family-related functions derived from animal model systems: studies on development, cardiovascular disease, and cancer metastasis exemplified

“…The function of Nme protein as an endocytic factor was noted more than 10 years ago in Drosophila (Dammai et al 2003;Krishnan et al 2001). More recent genetic studies have further supported a more general role in vesicular transport (Feng et al 2014;Hippe et al 2011a;Hippe et al 2011b;Hippe et al 2009).…”

“…Early studies in Drosophila showed that awd mutant larval brain exhibited mitotic defects correlated with defective microtubule polymerization (Biggs et al 1990). Subsequently, awd has been implicated in the process of endocytosis in multiple tissues, including neurotransmitter uptake at the neuromuscular junctions (Krishnan et al 2001), surface receptor internalization that modulates the chemotaxis response in tracheal cell and border cell migration (Dammai et al 2003;Nallamothu et al 2008), recycling of adherens junction components (Woolworth et al 2009), and promotion of early-to-late endosome transition that is critical for Notch signaling in follicle cells and in imaginal discs (Ignesti et al 2014). These endocytic functions were associated with the functions of dynamin and Rab5, suggesting a GTP-supplier function for these monomeric GTPases.…”

Nucleoside diphosphate kinases (NDPKs) in animal development

“…Ramaswami's laboratory was interested in identifying genes that regulate neurotransmission at synaptic junctions using forward genetic approaches [40]. In synaptic vesicle recycling and cellular trafficking, endocytosis plays a key role.…”

“…In synaptic vesicle recycling and cellular trafficking, endocytosis plays a key role. Pioneering work in Ramaswami's laboratory revealed that AWD/NM23 is an essential component of endocytosis: AWD was identified as a factor required for dynamindependent synaptic vesicle recycling [40]. Dynamin is a GTPase functioning in a later stage of endocytosis in eukaryotic cells where it pinches off the nascent vesicle by constricting its neck.…”

Interaction of nucleoside diphosphate kinase B with heterotrimeric G protein βγ dimers: consequences on G protein activation and stability

“…In mammalian tissues, the cytosolic enzyme forms heterohexamers of 17-21 kDa subunits (Gilles et al 1991;Janin et al 2000). These are composed of different combinations of the three major isoforms, NDPK A, B and C. In addition to NTP synthesis, NDPKs are involved in a variety of processes in cellular physiology, including tumour metastasis (Steeg et al 1988), development (Rosengard et al 1989), gene regulation (Postel 2003), apoptosis (Fan et al 2003), endocytosis (Krishnan et al 2001;Palacios et al 2002), vesicular transport from the endoplasmatic reticulum (Kapetanovich et al 2005) and regulation of the cystic fibrosis transmembrane conductance regulator (Crawford et al 2006a).…”