Clusters depolymerization

Other components, such as a-actinin and actin-related proteins (or ARPs), may also be recruited to the polymerization zone, whereas depolymerizing factors such as ADF and cofilin are apt to be selectively localized in the depolymerization zone. Note Agents that disrupt the formation of activated ABM clusters will also suppress the rate of assembly in the polymerization zone. See ABM-1 ABM-2 Sequences In Actin-Based Motors... 

The number of aromatic clusters, //cl, revealed that molecules in Light, Middle and Heavy fractions consisted of one aromatic cluster, while about 30% of the molecules in the Resid have, on the average, two clusters. Overall, molecules in HVL-P have one aromatic cluster, i.e., HVL-P is apparently a product of almost complete depolymerization of the coal. 

Table V shows yields and structural parameters of SP-300 fractions. These fractions were black solid materials like the feed coal, as compared to dark-brown viscous liquids of the HVL-P fractions. The overall average molecular weight of SP-300 was more than three times that of HVL-P. SP-300 fractions have much larger R, RN and //cl than HVL-P fractions. The //cl values disclosed that there were, on the average, 2.8 aromatic clusters per molecule in SP-300, as compared to 1.1 aromatic clusters per molecule in HVL-P. Thus SP-300 fractions are high molecular weight materials,in which the degree of depolymerization is relatively low. This in turn suggests that SP-300 has retained more of the original structures of the parent coal than has HVL-P.

The partial effect of actin depolymerization on synaptic clustering of NMDA receptors is consistent with multiple complex interactions between NMDA receptors and the cytoskeleton. NMDA receptors may also associate with microtubules, albeit indirectly via PSD-95 and CRIPT and MAPIA, and they may even interact with neurofilaments via less well-defined mechanisms. The relevance of microtubules and neurofilaments at postsynaptic sites is still controversial. 

Gerisch, G., Bretschneider,T.,Muller-Tauben-berger. A., Simmeth, E., Ecke, M., Diez, S., and Anderson, K. (2004) Mobile actin clusters and traveling waves in cells recovering from actin depolymerization. Biophys. J. 87, 3493-3503... 

Ochiai, A., Itoh, T., Kawamata, A., Hashimoto, W, and Murata, K. (2007). Plant cell wall degradation by saprophytic Bacillus subtilis strains Gene clusters responsible for rhamnogalacturo-nan depolymerization. zI/jjv/. Environ. Microbiol 73, 3803-3813. 

Cluster-cluster growth is expected to pertain when there is not a continuous source of monomers and when there is no mechanism favoring condensation predominantly between low- and high-molecular-weight species. Re-examination of the Si NMR spectra shown in Fig. 33 shows that these conditions may exist under acidic conditions. At pH 1 the solution is depleted of monomers at = 0.9, yet the concentration of Q species is much less than under neutral conditions. In fact the monomers are essentially depleted for 0.01 [111]. Under strongly acidic conditions the hydrolysis reaction is complete long before the gel point (see Fig. 29), which indicates that the rate of condensation is low with respect to the rate of hydrolysis. Below about pH 3, the depolymerization reaction is minimized. Below about pH 2, the isoelectric point of silica, condensation occurs by a mechanism involving a protonated silanol or alkoxide species. 

Fig. 8 Confocal fluorescence microscopy of B50 neuroblastoma cells, (a, b) Immunolabeling of mtHSP70 green) in B50 cells in controls (a) and cisPt-treated cells (b). After cisPt, mitochondria are clustered around the nucleus and form dense masses in the cytoplasm (b). Nuclei are counterstained with Hoechst blue), (c, d) Double immunolabeling of filamentous actin red) and a-tubulin green) in B50 control cells (c) and in 48 h cisPt-treated cells (d). CisPt-induced cytoskeleton damage leads tubulin to reorganize into thick bundles (e) and to disruption of filamentous actin microfilaments and accumulation of depolymerized actin at cell periphery (f).

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