C-terminal amino acids are essential for human heat shock protein 70 dimerization

Guillaume Marcion (1) , Renaud Seigneuric (1) , Evelyne Chavanne (2) , Yves Artur (2) , Loïc Briand (2) , Tarik Hadi (1) , Jessica Gobbo (1, 3) , Carmen Garrido (1, 3) , Fabrice Neiers (2)

1 INSERM - Institut National de la Santé et de la Recherche Médicale
2 CSGA - Centre des Sciences du Goût et de l'Alimentation [Dijon]
3 UNICANCER/CRLCC-CGFL - Centre Régional de Lutte contre le cancer Georges-François Leclerc [Dijon]

The human inducible heat shock protein 70 (hHsp70), which is involved in several major pathologies, including neurodegenerative disorders and cancer, is a key molecular chaperone and contributes to the proper protein folding and maintenance of a large number of protein structures. Despite its role in disease, the current structural knowledge of hHsp70 is almost exclusively based on its Escherichia coli homolog, DnaK, even though these two proteins only share ~50 % amino acid identity. For the first time, we describe a complete heterologous production and purification strategy that allowed us to obtain a large amount of soluble, full-length, and non-tagged hHsp70. The protein displayed both an ATPase and a refolding activity when combined to the human Hsp40. Multi-angle light scattering and bio-layer interferometry analyses demonstrated the ability of hHsp70 to homodimerize. The role of the C-terminal part of hHsp70 was identified and confirmed by a study of a truncated version of hHsp70 that could neither dimerize nor present refolding activity.

Mots clés: hspa1a; hsp70; cancer; monomer; dimer

Domaines: Médecine humaine et pathologie; Cancer

Guillaume Marcion, Renaud Seigneuric, Evelyne Chavanne, Yves Artur, Loïc Briand, et al.. C-terminal amino acids are essential for human heat shock protein 70 dimerization. Cell Stress and Chaperones, 2014, 20 (1), pp.61-72. ⟨10.1007/s12192-014-0526-3⟩. ⟨hal-01187031⟩