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- Hernandez-Hernandez, A, et al.
(författare)
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The central element of the synaptonemal complex in mice is organized as a bilayered junction structure
- 2016
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Ingår i: Journal of cell science. - : The Company of Biologists. - 1477-9137 .- 0021-9533. ; 129:11, s. 2239-2249
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Tidskriftsartikel (refereegranskat)abstract
- The synaptonemal complex (SC) transiently stabilizes pairing interactions between homologous chromosomes during meiosis. Assembly of the SC is mediated through integration of opposing transverse filaments (TF) into a central element (CE), a process that is poorly understood. We have here analyzed the localization of the TF protein SYCP1 and the CE proteins SYCE1, SYCE2 and SYCE3 within the central region of the SC in mouse spermatocytes using immunoelectron microscopy. Distribution of immuno-gold particles in a lateral view of the SC, supported by protein interaction data, suggest that the N-terminal region of SYCP1 and SYCE3 form a joint bilayered central structure and that SYCE1 and SYCE2 localize in between the two layers. We find that disruption of SYCE2 and TEX12 (a fourth CE protein) localization to the CE abolishes central alignment of the N-terminal region of SYCP1. Thus, our results show that all four CE proteins in an interdependent manner contribute to stabilization of opposing N-terminal regions of SYCP1, forming a bilayered TF-CE junction structure that promotes SC formation and synapsis.
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- Narangifard, A., et al.
(författare)
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Human skin barrier formation takes place via a cubic to lamellar lipid phase transition as analyzed by cryo-electron microscopy and EM-simulation
- 2018
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827 .- 1090-2422. ; 366:2, s. 139-151
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Tidskriftsartikel (refereegranskat)abstract
- The skin's permeability barrier consists of stacked lipid sheets of splayed ceramides, cholesterol and free fatty acids, positioned intercellularly in the stratum corneum. We report here on the early stage of skin barrier formation taking place inside the tubuloreticular system in the secretory cells of the topmost viable epidermis and in the intercellular space between viable epidermis and stratum corneum. The barrier formation process was analysed in situ in its near-native state, using cryo-EM combined with molecular dynamics modeling and EM simulation. Stacks of lamellae appear towards the periphery of the tubuloreticular system and they are closely associated with granular regions. Only models based on a bicontinuous cubic phase organization proved compatible with the granular cryo-EM patterns. Only models based on a dehydrated lamellar phase organization agreed with the lamellar cryo-EM patterns. The data support that human skin barrier formation takes place via a cubic to lamellar lipid phase transition.
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