Abstract
The Golgi apparatus has attracted intense attentions due to its fascinating morphology and vital role as the pivot of cellular secretory pathway since its discovery. However, its complex structure at the molecular level remains elusive due to limited approaches. In this study, the structure of Golgi apparatus, including the Golgi stack, cisternal structure, relevant tubules and vesicles, were directly visualized by high-resolution atomic force microscope. We imaged both sides of Golgi apparatus membranes and revealed that the outer leaflet of Golgi membranes is relatively smooth while the inner membrane leaflet is rough and covered by dense proteins. With the treatment of methyl-β-cyclodextrin and Triton X-100, we confirmed the existence of lipid rafts in Golgi apparatus membrane, which are mostly in the size of 20 nm –200 nm and appear irregular in shape. Our results may be of significance to reveal the structure-function relationship of the Golgi complex and pave the way for visualizing the endomembrane system in mammalian cells at the molecular level.
Highlights
The Golgi apparatus is a key organelle of the endomembrane system, locating at the pivot of the classical secretory pathway
atomic force microscopy (AFM) Image of Golgi Apparatus The Golgi membrane fractions were prepared by sucrose density gradient centrifugation
To obtain the detailed information about the Golgi membrane fractions, we imaged them by AFM under near-native conditions
Summary
The Golgi apparatus is a key organelle of the endomembrane system, locating at the pivot of the classical secretory pathway. The Golgi apparatus is a dynamic organelle, responsible for receiving, processing, and sorting newly synthesized proteins and lipids through the secretory pathway [2]. The proteins in Golgi membranes are the basis for the Golgi apparatus to perform important intracellular functions, such as membrane sorting, membrane traffic and signal transduction. Biological membranes consisting of various lipids and proteins are not homogeneous [6,7], which is considered as a requirement to perform its functions [8,9]. It is reported that in mammalian cells lipid rafts are first assembled in the Golgi complex where sphingolipids are synthesized [11,12]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
