Vesicles types

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. 

Compound Lipid Vesicle type PAaw log Kimw (neutral species) Amw Ref. 

In addition to the micelle-type assemblies described above, there has been significant interest in developing conditions for forming vesicle-type assemblies from amphiphilic polymers. Polymeric vesicles are formed by bolamphiphilic block... 

Cell on the right fusion-competence. Cell on the left migration status. Note the different colors representing different vesicle types, each of which is characterized by a unique protein assembly. 

As shown in Figure 9.3, the two cells show a clearly different subcellular order of the different vesicle types. The latter signify different functional states of these cells cell on the right (fusion competence), cell on the left (migration status). 

Vesicle Type Creation Method Size Range (0 in nm) Capacity (i/moi iipid) Advantages Disadvantages... 

The pineal glands of rats 12-28 months old exhibited regressive changes of different intensity with age (Boya and Calvo 1984). In type I pinealocytes there was a marked increase in dense bodies as well as the occasional appearance of wide cell profiles full of vesicles. Type II pinealocytes showed nuclear infoldings and cytoplasmic deposits of lipofuscin. 

The protocols outlined in this article were used to characterize the regulation of cytoskeletal dynamics associated with COPI vesicle formation on Golgi membranes. With some modification it seems likely that related approaches could be used to elucidate the role of the cytoskeleton with other vesicle types or on other organelles. Combining these cell-free approaches with genetic and whole-cell studies will ultimately provide a much clearer picture of the interface between vesicular transport and the cytoskeleton. 

Figure 10 Representative TEM images of various vesicle types (a) uniform vesicles, (b) polydisperse vesicles, (c) entrapped vesicles, (d) hollow concentric vesicles, (e) onion-like vesicles, (f) vesicles with tubes in the walls. (Reproduced from Ref. 31. Wiley Periodicals, Inc, 2004.)...

Sample Vesicle type Relative abundance Average diameter (p.m)... 

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