Intercellular trafficking

Fig. 2 Intercellular trafficking and thiamine and thiamine esters in brain. TMP thiamine monophosphate, TDP thiamine diphosphate, TTP thiamine triphosphate, TPKinase thiamine pyrophosphokinase...

Figure 2.13 Putative localization and intercellular trafficking of monoterpene indole alkaloids in Catharanthus roseus. (After Facchini and De Luca, 2008 Murata et a ., 2008.)...

Varki, A. (1992). Role of oligosaccharides in the intracellular and intercellular trafficking of mammalian glycoproteins. In Cell Surface Carbohydrates and Cell Development. M.Fukuda, ed. (London CRC Press), pp. 25 69. 

P-GP is highly expressed at the luminal surface of the capillary endothelial cells of testis capillaries where it appears to limit the exposure of the tissue to a number of substrates (e.g., ivermectin, vinblastine, and nelfma-vir) (Leslie et al., 2005). The relatively high constitutive expression of MRPl is cell-type specific and appears to play a role in the intercellular trafficking of steroids (Leslie et al., 2005). The low expression level of BGRP and MRP2 in the blood-testis barrier suggests a functional role unlikely (Leslie etal., 2005). 

Elliott G, O Hare P (1997). Intercellular trafficking and protein delivery by a herpesvirus structural protein. Cell. 88 223-233. 

Since adhesion molecules are of pivotal importance in cell trafficking and thus inflammation, they could constitute good therapeutic targets in RA. In fact, a murine mAb to intercellular adhesion molecule (ICAM)-l proved to lead to clinical improvement, (140) but repeated administration may have less effects, and the side-effect profile was also of major concern (141). Thus, anti-ICAM-1 may not be the strategy of choice. In this context it should be mentioned that TNFa blockade leads not only to clinical benefit but also to reduction of adhesion molecule expression. 

Figure 7.9 Intercellular and subcellular trafficking in alkaloid biosynthesis. A. Tropane alkaloid biosynthesis in Hyoscyamus muticus. B. Terpenoid indole alkaloid biosynthesis in Catharanthus roseus. C. Trafficking of the berberine bridge enzyme in Papaver somniferum cell cultures.

Typically, the presynaptic ending is further distinguished from the postsynaptic component by the conspicuous presence of neurotransmitter-filled vesicles. In response to presynaptic membrane depolarization, the vesicles exocytose their contents into the cleft through complicated membrane-trafficking events. The presynaptic axon terminal (bouton) of the presynaptic component also contains other organelles such as mitochondria, smooth endoplasmic reticulum, microtubules, and neurofilaments. The presynaptic membrane is variably populated by docking/fusion apparatus, ion channels, and other protein constituents. The 20-30 nM wide synaptic cleft separates the pre- and postsynaptic membranes and generally contains a dense plaque of intercellular material that includes microfilaments. 

Ras trafficking to cellular membranes can be measured by fluorescence recovery after photobleaching (FRAP) and fluorescence loss in photobleaching (FLIP) (54). Both techniques rely on the expression of fluorescent-labeled Ras proteins to monitor different parameters of Ras movement across and between cellular membranes. FRAP involves photobleaching a membrane subdomain and measuring the kinetics of fluorescence recovery—and hence Ras trafflcking—into the bleached area. With FLIP, a cellular membrane is photobleached repeatedly and the subsequent intercellular movement of the photobleached area is monitored. 

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