Recently, we highlighted that the ganglioside GM1 promotes neuroblastoma cells differentiation by activating the TrkA receptor through the formation of a TrkA–GM1 oligosaccharide complex at the cell surface. To study the TrkA–GM1 interaction, we synthesized two radioactive GM1 derivatives presenting a photoactivable nitrophenylazide group at the end of lipid moiety, 1 or at position 6 of external galactose, 2; and a radioactive oligosaccharide portion of GM1 carrying the nitrophenylazide group at position 1 of glucose, 3. The three compounds were singly administered to cultured neuroblastoma Neuro2a cells under established conditions that allow cell surface interactions. After UV activation of photoactivable compounds, the proteins were analyzed by PAGE separation. The formation of cross-linked TrkA–GM1 derivatives complexes was identified by both radioimaging and immunoblotting. Results indicated that the administration of compounds 2 and 3, carrying the photoactivable group on the oligosaccharide, led to the formation of a radioactive TrkA complex, while the administration of compound 1 did not. This underlines that the TrkA–GM1 interaction directly involves the GM1 oligosaccharide, but not the ceramide. To better understand how GM1 relates to the TrkA, we isolated plasma membrane lipid rafts. As expected, GM1 was found in the rigid detergent-resistant fractions, while TrkA was found as a detergent soluble fraction component. These results suggest that TrkA and GM1 belong to separate membrane domains: probably TrkA interacts by ‘flopping’ down its extracellular portion onto the membrane, approaching its interplay site to the oligosaccharide portion of GM1. (Figure presented.).

GM1 promotes TrkA-mediated neuroblastoma cell differentiation by occupying a plasma membrane domain different from TrkA / E. Chiricozzi, E.D. Biase, M. Maggioni, G. Lunghi, M. Fazzari, D.Y. Pomè, R. Casellato, N. Loberto, L. Mauri, S. Sonnino. - In: JOURNAL OF NEUROCHEMISTRY. - ISSN 0022-3042. - 149:2(2019 Apr), pp. 231-241. [10.1111/jnc.14685]

GM1 promotes TrkA-mediated neuroblastoma cell differentiation by occupying a plasma membrane domain different from TrkA

E. Chiricozzi
Primo
;
E.D. Biase
Secondo
;
M. Maggioni;G. Lunghi;M. Fazzari;D.Y. Pomè;R. Casellato;N. Loberto;L. Mauri
Penultimo
;
S. Sonnino
Ultimo
2019

Abstract

Recently, we highlighted that the ganglioside GM1 promotes neuroblastoma cells differentiation by activating the TrkA receptor through the formation of a TrkA–GM1 oligosaccharide complex at the cell surface. To study the TrkA–GM1 interaction, we synthesized two radioactive GM1 derivatives presenting a photoactivable nitrophenylazide group at the end of lipid moiety, 1 or at position 6 of external galactose, 2; and a radioactive oligosaccharide portion of GM1 carrying the nitrophenylazide group at position 1 of glucose, 3. The three compounds were singly administered to cultured neuroblastoma Neuro2a cells under established conditions that allow cell surface interactions. After UV activation of photoactivable compounds, the proteins were analyzed by PAGE separation. The formation of cross-linked TrkA–GM1 derivatives complexes was identified by both radioimaging and immunoblotting. Results indicated that the administration of compounds 2 and 3, carrying the photoactivable group on the oligosaccharide, led to the formation of a radioactive TrkA complex, while the administration of compound 1 did not. This underlines that the TrkA–GM1 interaction directly involves the GM1 oligosaccharide, but not the ceramide. To better understand how GM1 relates to the TrkA, we isolated plasma membrane lipid rafts. As expected, GM1 was found in the rigid detergent-resistant fractions, while TrkA was found as a detergent soluble fraction component. These results suggest that TrkA and GM1 belong to separate membrane domains: probably TrkA interacts by ‘flopping’ down its extracellular portion onto the membrane, approaching its interplay site to the oligosaccharide portion of GM1. (Figure presented.).
GM1; GM1 oligosaccharide; lipid rafts; neurodifferentiation; TrkA; Biochemistry; Cellular and Molecular Neuroscience
Settore BIO/10 - Biochimica
   Dipartimenti di Eccellenza 2018-2022 - Dipartimento di FILOSOFIA
   MINISTERO DELL'ISTRUZIONE E DEL MERITO
apr-2019
Article (author)
File in questo prodotto:
File Dimensione Formato  
1_Main Test_Chiricozzi.pdf

accesso aperto

Tipologia: Pre-print (manoscritto inviato all'editore)
Dimensione 256.12 kB
Formato Adobe PDF
256.12 kB Adobe PDF Visualizza/Apri
jnc.14685.pdf

accesso riservato

Tipologia: Publisher's version/PDF
Dimensione 871.39 kB
Formato Adobe PDF
871.39 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/658731
Citazioni
  • ???jsp.display-item.citation.pmc??? 20
  • Scopus 33
  • ???jsp.display-item.citation.isi??? 30
social impact