Reorganization of plasma membrane lipid domains during conidial germination.
Neurospora crassa, a filamentous fungus, in the unicellular conidial stage has ideal features to study sphingolipid (SL)-enriched domains, which are implicated in fundamental cellular processes ranging from antifungal resistance to apoptosis. Several changes in lipid metabolism and in the membrane composition of N. crassa occur during spore germination. However, the biophysical impact of those changes is unknown. Thus, a biophysical study of N. crassa plasma membrane, particularly SL-enriched domains, and their dynamics along conidial germination is prompted. Two N. crassa strains, wild-type (WT) and slime, which is devoid of cell wall, were studied. Conidial growth of N. crassa WT from a dormancy state to an exponential phase was accompanied by membrane reorganization, namely an increase of membrane fluidity, occurring faster in a supplemented medium than in Vogel's minimal medium. Gel-like domains, likely enriched in SLs, were found in both N. crassa strains, but were particularly compact, rigid and abundant in the case of slime cells, even more than in budding yeast Saccharomyces cerevisiae. In N. crassa, our results suggest that the melting of SL-enriched domains occurs near growth temperature (30°C) for WT, but at higher temperatures for slime. Regarding biophysical properties strongly affected by ergosterol, the plasma membrane of slime conidia lays in between those of N. crassa WT and S. cerevisiae cells. The differences in biophysical properties found in this work, and the relationships established between membrane lipid composition and dynamics, give new insights about the plasma membrane organization and structure of N. crassa strains during conidial growth.
Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Filipa C
FC
Santos
IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal.
Andreia S
AS
Fernandes
Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Catarina A C
CAC
Antunes
Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Filipe P
FP
Moreira
IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS-Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
Arnaldo
A
Videira
Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
H Susana
HS
Marinho
Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal. Electronic address: rodrigo.almeida@fc.ul.pt.
Rodrigo F M
RFM
de Almeida
D002462:Cell Membrane / Q000378:metabolism* / Q000502:physiology*; D002473:Cell Wall / Q000378:metabolism / Q000502:physiology; D005656:Fungal Proteins / Q000378:metabolism; D008560:Membrane Fluidity / Q000502:physiology; D008563:Membrane Lipids / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism / Q000502:physiology; D009492:Neurospora crassa / Q000254:growth & development* / Q000378:metabolism* / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D013107:Sphingolipids / Q000378:metabolism*; D013170:Spores / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D013172:Spores, Fungal / Q000254:growth & development / Q000378:metabolism / Q000502:physiology
D005656:Fungal Proteins; D008563:Membrane Lipids; D013107:Sphingolipids
Ergosterol; Fluorescence spectroscopy; Fungal sphingolipids; Lipid domains/rafts; Neurospora crassa; Saccharomyces cerevisiae