Exploring structural aspects of the human Golgi matrix protein GRASP55 in solution

Autor(es)

Thirupathi Reddy, S. ^[1] ; Santos Mendes, Luis Felipe ^[1] ; Fontana, Natalia Aparecida ^[1] ; Costa-Filho, Antonio Jose ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Phys, Ribeirao Preto Sch Philosophy Sci & Literature, Av Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: International Journal of Biological Macromolecules; v. 135, p. 481-489, AUG 15 2019.
• Citações Web of Science: 0

Resumo

In mammals, the Golgi apparatus is the central hub for intracellular trafficking, sorting and post-translational modifications of proteins and lipids. Golgi reassembly and stacking proteins (GRASPs) are somehow involved in Golgi stacking, which is relevant for its proper function, and also in unconventional protein secretion. However, the structural details on how GRASPs accomplish those tasks are still elusive. Here, we have explored the biochemical and biophysical properties of human full-length GRASP55 in solution. Sequence-based analyses and circular dichroism spectroscopy suggest that GRASP55 presents multiple intrinsically disordered sites, although keeping considerable contents of regular secondary structure. Size exclusion chromatography and multiple-angle light scattering show that GRASP55 are monomers in solution. Urea denaturation of GRASP55 suggests the transition to the unfolded state is a cooperative process. Differential scanning calorimetry analysis displays two endothermic transitions for GRASP55, indicating the existence of an intermediate state prior to unfolding. Thioflavin T fluorescence suggests GRASP55 intermediate can be aggregates/fibrils. Transmission electron microscopy and fluorescence lifetime imaging microscopy prove GRASP55 forms large amorphous aggregates but not amyloid-like fibrils in the intermediate state. These results could be helpful in discussing the proper function of human GRASP55 in the Golgi organization as well as unconventional secretion of proteins. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 16/23863-2 - Interações moleculares da proteína de organização e compactação do Golgi (GRASP) de Saccharomyces cerevisiae
• Beneficiário: Natália Aparecida Fontana
• Linha de fomento: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 17/12146-0 - Explorando as propriedades biofísicas da proteína humana de organização e compactação do Golgi (GRASP55) e suas interações com modelos de membrana
• Beneficiário: Thirupathi Reddy Soudherpally
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/24669-8 - Desvendando as bases moleculares de processos iniciais da secreção de proteínas em humanos utilizando técnicas biofísicas
• Beneficiário: Luis Felipe Santos Mendes
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/16812-0 - EMU concedido no processo 2014/15546-1: SEC-MALS
• Beneficiário: Richard Charles Garratt
• Linha de fomento: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
• Processo FAPESP: 15/50366-7 - Resolving mechanistic details of peptide transport across membranes using crystallographic and non-crystallographic structural biology approaches
• Beneficiário: Antonio José da Costa Filho
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/20367-3 - Estudos estruturais e funcionais da proteína de organização e compactação do Golgi (GRASP) de Cryptococcus neoformans
• Beneficiário: Antonio José da Costa Filho
• Linha de fomento: Auxílio à Pesquisa - Regular