Granule translocation

Covian-Nares F, Martinez-Cadena G, Lopez-Godinez J, Voronina E, Wessel GM, Garda-Soto J. 2004. A Rho-signaling pathway mediates cortical granule translocation in the sea urchin oocyte. Mech Dev 121(3) 225-235. 

Adenosine is not a classical neurotransmitter because it is not stored in neuronal synaptic granules or released in quanta. It is generally thought of as a neuromodulator that gains access to the extracellular space in part from the breakdown of extracellular adenine nucleotides and in part by translocation from the cytoplasm of cells by nucleoside transport proteins, particularly in stressed or ischemic tissues (Fig. 17-2C). Extracellular adenosine is rapidly removed in part by reuptake into cells and conversion to AMP by adenosine kinase and in part by degradation to inosine by adenosine deaminases. Adenosine deaminase is mainly cytosolic but it also occurs as a cell surface ectoenzyme. 

Figure 5.7. Translocation of cytochrome b to the plasma membrane. In non-stimulated cells, only a small proportion of the total cellular pool of cytochrome b is present on the plasma membrane. The major pool of this cytochrome is located on the membranes of specific granules, gelatinase-containing granules and secretory vesicles. During activation (e.g. by fMet-Leu-Phe or PMA) or priming (e.g. by cytokines), some of these subcellular pools of cytochrome b molecules are translocated to the plasma membrane, thereby increasing the level of surface cytochrome b.

In order to function efficiently, myeloperoxidase must be translocated from its intracellular location, the azurophilic granule, to the site of NADPH oxi-... 

Primary alcohols inhibit the up-regulation of CR3 (complement receptor) molecules on the plasma membrane during neutrophil activation, indicating that PLD products are required for the translocation of specific granules,... 

Maridonneau-Parini, I., de Gunzburg, J. (1992). Association of rapl and rap2 proteins with the specific granules of human neutrophils. Translocation to the plasma membrane during cell activation. J. Biol. Chem. 267,6396-402. 

In primary cultures of neonatal cerebellar granule neurons, all Ca2+ sensors, calmodulin, protein kinases C (PKC), and the p21(ras)/phosphatidylinositol 3 -kinase (Ptdlns-3K)/Akt pathway, converge towards NF-kB at the levels of nuclear translocation as well as transcription. The duration of NF-kB activation is a critical determinant for sensitivity toward excitotoxic stress and is dependent on the different upstream and downstream signaling associated with various kinases. This is in contrast to studies in non-neuronal cells, which either do not respond to Ca2+ or do not simultaneously activate all three cascades (Lilienbaum and Israel, 2003). Collective evidence suggests that brain inflammatory processes differ from systemic inflammation not only in the involvement of various types of neural cells but also in differences in response to second messengers. 

Colchicine inhibits the release of histamine-containing granules from mast cells, the secretion of insulin from P-cells of pancreatic islets, and the movement of melanin granules in melanophores. Although it is questionable whether these effects occur at clinically achieved concentrations of colchicine, all these processes may involve the translocation of granules by the microtubular system. 

Sorcin is a 22-kDa small protein modulating the sarcoplasmic reticulum (SR) calcium channel ryanodine receptor (RyR). It also interacts with annexin A7. Grancalcin is a 28-kDa protein with unknown functions. It displays a calcium-dependent translocation to the granules and plasma membrane of neutrophils. Both proteins are reported to form homodimers. However, recent studies indicate that sorcin and grancalcin can also form heterodimers and can be coimmunoprecipitated, suggesting that they may function together. ... 

---