HTT (huntingtin) and RAB7 co-migrate retrogradely on a signaling LAMP1-containing late endosome during axonal injury. Issue 4 (3rd April 2023)

• Record Type: Journal Article
• Authors: Krzystek, Thomas J.; White, Joseph A.; Rathnayake, Rasika; Thurston, Layne; Hoffmar-Glennon, Hayley; Li, Yichen; Gunawardena, Shermali
• Is Part Of: Autophagy. Volume 19:Issue 4(2023)
• Page Start: 1199
• Page End: 1220
• Publication Date: 2023-04-03
• Subjects: Axonal injury -- axonal transport -- Drosophila -- endolysosomes -- huntingtin -- signaling endosome; Autophagic vacuoles -- Periodicals; Apoptosis -- Periodicals; Cell death -- Periodicals; Lysosomes -- Periodicals; Degeneration (Pathology) -- Periodicals; Autophagy -- Periodicals; Cell Death -- Periodicals; Lysosomes -- Periodicals; Periodicals; 571.936
• DOI: 10.1080/15548627.2022.2119351
• Languages: English
• ISSNs: 1554-8627

Abstract

ABSTRACT: HTT (huntingtin) is a 350-kDa protein of unknown function. While HTT moves bidirectionally within axons and HTT loss/reduction causes axonal transport defects, the identity of cargo-containing vesicles that HTT helps move remain elusive. Previously, we found an axonal retrogradely moving HTT-Rab7 vesicle complex; however, its biological relevance is unclear. Using Drosophila genetics, in vivo microscopy, membrane isolation and pharmacological inhibition, here we identified that adaptors Hip1 and Rilpl aid the retrograde motility of LAMP1-containing HTT-Rab7 late endosomes, not autophagosomes. Reduction of Syx17 and chloroquine- or bafilomycin A1 -mediated pharmacological inhibition, but not reduction of Atg5, disrupted the in vivo motility of these vesicles. Further, because HTT-Rab7 vesicles colocalized with long-distance signaling components (BMP signaling: tkv-wit, injury: wnd) and move in a retrograde direction after Drosophila nerve crush, we propose that these vesicles likely traffic damage signals following axonal injury. Together, our findings support a previously unknown role for HTT in the retrograde movement of a Rab7-LAMP1-containing signaling late endosome. Abbreviations: Atg5: Autophagy-related 5; Atg8a: Autophagy-related 8a; AL: autolysosome; AP: autophagosome; BAF1: bafilomycin A1 ; BDNF: brain derived neurotrophic factor; BMP: bone morphogenetic protein; Cyt-c-p: Cytochrome c proximal; CQ: chloroquine; DCTN1: dynactin 1; Dhc: dynein heavy chain; EE: early endosome; DYNC1I1: dynein cytoplasmic 1 intermediate chain 1; HD: Huntington disease; HIP1/Hip1: huntingtin interacting protein 1; HTT/htt: huntingtin; iNeuron: iPSC-derived human neurons; IP: immunoprecipitation; Khc: kinesin heavy chain; KIF5C: kinesin family member 5C; LAMP1/Lamp1: lysosomal associated membrane protein 1; LE: late endosome; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAP3K12/DLK: mitogen-activated protein kinase kinase kinase 12; MAPK8/JNK/bsk: mitogen-activated protein kinase 8/basket; MAPK8IP3/JIP3: mitogen-activated protein kinase 8 interacting protein 3; NGF: nerve growth factor; NMJ: neuromuscular junction; NTRK1/TRKA: neurotrophic receptor tyrosine kinase 1; NRTK2/TRKB: neurotrophic receptor tyrosine kinase 2; nuf: nuclear fallout; PG: phagophore; PtdIns3P: phosphatidylinositol-3-phosphate; puc: puckered; ref(2)P: refractory to sigma P; Rilpl: Rab interacting lysosomal protein like; Rip11: Rab11 interacting protein; RTN1: reticulon 1; syd: sunday driver; SYP: synaptophysin; SYT1/Syt1: synaptotagmin 1; STX17/Syx17: syntaxin 17; tkv: thickveins; VF: vesicle fraction; wit: wishful thinking; wnd: wallenda