Self-propelling vesicles define glycolysis as the minimal energy machinery for neuronal transport

Abstract

The glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) facilitates fast axonal transport in neurons. However, given that GAPDH does not produce ATP, it is unclear whether glycolysis per se is sufficient to propel vesicles. Although many proteins regulating transport have been identified, the molecular composition of transported vesicles in neurons has yet to be fully elucidated. Here we selectively enrich motile vesicles and perform quantitative proteomic analysis. In addition to the expected molecular motors and vesicular proteins, we find an enrichment of all the glycolytic enzymes. Using biochemical approaches and super-resolution microscopy, we observe that most glycolytic enzymes are selectively associated with vesicles and facilitate transport of vesicles in neurons. Finally, we provide evidence that mouse brain vesicles produce ATP from ADP and glucose, and display movement in a reconstituted in vitro transport assay of native vesicles. We conclude that transport of vesicles along microtubules can be autonomous.

ATP-Citrate lyase fuels axonal transport across species

“…Elongator subunits and Atat1 have been detected in protein extracts from purified motile vesicles (16,30) and the present study confirms those data and shows that a functional pool of Acly is also predominantly enriched in the vesicular fraction of mouse cerebral cortical extracts. Therefore, we postulate that an Elongator/Acly/Atat1 (EAA) signaling pathway may directly act at vesicles to promote MT acetylation, further supporting their non-canonical role as a platform for local signaling and for regulating axonal transport in particular ( Figure 4g).…”

“…Convergent observations support a role for Elongator in intracellular transport in the nervous system as Elp3 is enriched at the pre-synaptic side of neuromuscular junction buttons in flies, where its expression is required for synapse integrity and activity (14,15). Elongator subunits are also detected in protein extracts from purified motile vesicles isolated from the mouse cerebral cortex (16), and they colocalize with the vesicular markers SV2 and RAB3A in human embryonic stem cells derived neurons (17). In humans, mutation of the gene coding for ELP1, underlies Familial dysautonomia (FD), a devastating disease that mostly affects the development and survival of neurons from the autonomic nervous systems (18,19).…”

Neuronal network maturation differently affects secretory vesicles and mitochondria transport in axons

“…The following constructs, LVs and AAVs were used: LV.PGK.GFP (pRRLSIN.cPPT.PGK-GFP.WPRE plasmid #12252 from Addgene), LV.CMV.mCherry (pLV-mCherry plasmid #36084 from Addgene), LV.PGK.iGluSnFR (pCMV(MinDis).iGluSnFR plasmid #41732 from Addgene cloned into pRRLSIN.cPPT.PGK-GFP.WPRE plasmid #12252 by replacing GFP with iGluSnFR), AAV5.SYN.GCaMP6f (#AV-5-PV2822 from U Penn Vector Core facility), LV.PGK.BDNF-mCh 36 and pDsRed2-Mito (plasmid #632421 from Clontech).…”

Neurobiology of axonal transport defects in motor neuron diseases: Opportunities for translational research?

“…One obvious way in which mitochondrial damage and concomitant mitochondrial transport defects and depletion of mitochondria from axons ( De Vos et al, 2007 , Vande Velde et al, 2011 , Magrané et al, 2012 , Wang et al, 2013 ) could affect the transport of other cargoes such as APP vesicles or signalling endosomes is by starving molecular motors of ATP. However, since it has been shown that neuronal BDNF, APP, and TrkB vesicles harbour most glycolytic enzymes and “self-propel” using their own source of glycolytic ATP independent of mitochondria ( Hinckelmann et al, 2016 , Zala et al, 2013 ) reduced axonal mitochondrial ATP production may not be sufficient to halt axonal transport. Alternatively, mitochondrial damage and/or lack of axonal mitochondria may affect transport by disturbance of calcium signalling.…”