Vesicles Golgi apparatus

Stelzner DJ. The relationship between synaptic vesicles, Golgi apparatus, and smooth endoplasmic reticulum A developmental study using the zinc iodide-osmium technique. Z Zellforsch 1971 120 332-345. 

Figure 20-8 (A) Electron micrograph showing a transverse section through part of the Golgi apparatus of an early spermatid. Cistemae of the ER, Golgi stacks (S), and vesicles (V) can be seen. Curved arrows point to associated tubules. Magnification X45/000.276 Courtesy of Y. Clermont. (B) Scheme showing functions of endoplasmic reticulum, transfer vesicles, Golgi apparatus, and secretion vesicles in the metabolism of glycoproteins.

At one surface the Golgi apparatus has a fresh face and at the opposite surface a mature face. Membranes at the fresh face resemble those of the endoplasmic reticulum, and membranes at the mature or secreting face are similar to the plasmalemma. This suggests that the Golgi apparatus operates as a membrane transformer from endoplasmic reticulum - vesicles - Golgi apparatus - vesicles - plasmalemma. 

LRRK2 protein is found in the cytosol and mitochondrial outer membrane (West et al., 2005), plasma membrane, lysosomes, endosomes, transport vesicles, Golgi apparatus, a cytoskeleton protein microtubule, synaptic vesicles, and lipid rafts (Biskup et al., 2006 Hatano et al., 2007). Interestingly, a-synuclein is also expressed in the presynaptic membranes and lipid rafts (Fortin et al., 2004). 

Smooth endoplasmic reticulum Primary or cytoplasmic vesicles Golgi apparatus and Golgi apparatus equivalents Secretory vesicles... 

I Vesicle — Golgi Apparatus -Vesicle— Single Clsterna -Continuous Transition Element-... 

Golgi apparatus A system of flattened membrane-bounded vesicles often stacked into a complex. Numerous small vesicles are found peripheral to the Golgi and contain secretory material packaged by the Golgi. Involved in the packaging and processing of macromolecules for secretion and for delivery to other cellular compartments. 

COPI vesicles mediate anterograde transport from the intermediate compartment to the Golgi, transport within the Golgi apparatus and retrograde transport back from the Golgi to the ER by the recruitment of soluble... 

The Golgi apparatus is a stack of flattened vesicles that functions in posttranslational processing and sorting... 

Once the proteins have passed the quality control system of the early secretory pathway, they are transported in vesicles via the individual compartments of the Golgi apparatus to the plasma membrane. Soluble proteins are transported in the vesicle lumen, membrane proteins are integrated in the vesicle membrane. The transport to the cell surface is the default pathway for secretory and membrane proteins. Proteins may also become part of one of the intracellular compartments along the secretory pathway, but only if they contain specific retention signals. 

In contrast to the small transmitter molecules, the neuropeptides are synthesized in the rough endoplasmic reticulum of the neuronal perikarya. They are enclosed in vesicles in the Golgi apparatus. The vesicles travel down to the terminals by axonal transport. 

Most proteins that are synthesized on membrane-bound polyribosomes and are destined for the Golgi apparatus or plasma membrane reach these sites inside transport vesicles. The precise mechanisms by which proteins synthesized in the rough ER are inserted into these vesicles are not known. Those involved in transport from the ER to the Golgi apparatus and vice versa—and from the Golgi to the plasma membrane— are mainly clathrin-free, unlike the coated vesicles involved in endocytosis (see discussions of the LDL receptor in Chapters 25 and 26). For the sake of clarity, the non-clathrin-coated vesicles will be referred to in... 

Many proteins synthesized on membrane-bound polyribosomes proceed to the Golgi apparatus and the plasma membrane in transport vesicles. 

FIGURE 1-6 A portion of a Golgi apparatus. The smooth-mem-braned cisternae appear beaded. The many circular profiles represent tangentially sectioned fenestrations and alveolate vesicles (primary lysosomes). Two of the latter can be seen budding from Golgi saccules (arrows). Mitochondria and a dense body (secondary lysosomes) are also present. x60,000. 

Biosynthetic and secretory cargo leaving the ER is packaged in COPII-coated vesicles for delivery to the Golgi complex 146 The Golgi apparatus is a highly polarized structure consisting of a series of flattened cisternae, usually located near the nucleus and the centrosome 146... 

Clathrin-coated vesicles mediate transport from the Golgi apparatus to endosomes, and from the plasma membrane to endosomes. A multi-subunit protein, clath-rin, constitutes the major protein of this vesicle type (see Ch. 2). Clathrin is composed of three large and three small polypeptide chains, which assemble to form a triskelion (Fig. 9-2). Regulatory mechanisms control the assembly and formation of a convex, polyhexa-pentagonal basketlike structure by these triskelions [5], This structure is responsible for the formation of coated pits on the cytosolic face of plasma membranes. 

The cytoskeleton appears to have a significant role in the localization of different organelles, as well as in the active transport of vesicles (see Chs 8 and 28). Both microtubules (MTs) and actin filaments appear to be involved in these processes. For example, through its association with the minus end of MTs, the Golgi apparatus is... 

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