Domains apical

Chapman and Liljas, Fig. 12. The shell-forming proteins of bluetongue virus and reovirus (a) bluetongue VPS protein (Grimes et al, 1998) (b) reovirus 11 protein (Reinisch et al., 2000). In the bluetongue VPS protein, three domains (apical, carapace, and dimerization domains) have been identified. The secondary structure elements have been colored to emphasize the general structural similarity between the two proteins. 

They are polarized—the plasma protein and lipids are distributed into three domains (apical, lateral and basolateral). 

The apical domain (residues 191-376) is essentially a four-layer structure comprising two p sheets sandwiched between a helices. One p sheet has... 

The apical domain (blue), which is a p sandwich flanked by a helices, is formed by the middle region of the polypeptide chain. The two linker regions between the equatorial and the apical domains form a small infermediate domain (purple) comprising three a helices. 

The cytoskeleton is involved in the maintenance of cell shape and cytoplasmic processes (e.g., microvilli). In polarized epithelial cells, distinct cyto-cortical cytoskeletal complexes are associated with the apical and basal-lateral domains of the plasma membrane (Rodriguez-Boulan and Nelson, 1989 Mays et al., 1994). 

Rao reported measurement of third-order optical non-linearity in the nanosecond and picosecond domains for phosphorus tetratolyl porphyrins bearing two hydroxyl groups in apical position [89]. Strong nonlinear absorption was found at both 532 nm and 600 nm. The high value of nonlinearity for nanosecond pulses is attributed to higher exited singlet and triplet states. Time resolved studies indicate an ultra-fast temporal evolution of the nonlinearity in this compound. 

Osteoclasts are multinucleated cells derived from pluripotent hematopoietic stem cells. Osteoclasts possess an apical membrane domain, exhibiting a ruffled border that plays a key role in bone resorption (Figure 48-12). A proton-translocating ATPase expels protons across the ruffled border into the resorption area, which is the microenvironment of low pH shown in the figure. This lowers the local pH to 4.0 or less, thus increasing the solubility of hydroxyapatite and allowing demineralization to occur. Lysosomal acid proteases are released that digest the now accessible matrix proteins. 

We have previously shown that a 209 amino acid region (aa288-497, asymmetric localization domain) of Insc is necessary and sufficient for apical cortical localization and for mitotic spindle orientation along the apical-basal axis (Tio et al 1999). In a yeast two-hybrid screen we identified Partner of Inscuteable (Pins), a novel 658aa protein with multiple repeats of the Tetratricopeptide (TPR) motif. Affinity purification experiments using embryonic extracts demonstrate that Pins complexes with Insc in vivo. In vitro protein interaction assays demonstrates that Pins interacts with the Insc asymmetric localization domain (see Yu et al 2000). 

In Pins - embryos the initiation steps of apical complex formation occur normally. However, this complex cannot be maintained in mitotic neuroblasts. Hence, the importance of the maintenance of this complex for asymmetric cell division can be ascertained by assessing how Pins- neural progenitors divide. Pins- embryos exhibit all of the defects seen in insc mutants. Mitotic spindle orientation is defective. In the cells of mitotic domain 9 the 90° reorientation, which normally occurs in wild-type resulting in the orientation of the spindle along the apical—basal axis (Fig. 3A), fails to occur in the mutant (Fig. 3B). Mitotic spindle orientation of neuroblasts in the segmented CNS, deduced from DNA staining, also often fails to... 

Chia We have looked at the potential phosphorylation sites of Insc, and this is the only apical complex component for which the functional domain has been defined. All the putative Cdc2 phosphorylation sites lie outside the region required for function (at least using an over-expression paradigm). For the other two known components, Baz and Pins, we don t know which the functional parts of the molecule are. It seems more appealing to think in terms of effects on the cytoskeleton, and in particular actin. 

C. Efflux Kinetics from the Apical Membrane Domain... 

Figure 5.10 Ribbon diagram of the transferrin receptor dimer depicted in its likely orientation with regard to the plasma membrane. One monomer is blue, the other is coloured according to domain the protease-like, apical and helical domains are red, green and yellow respectively the stalk is shown in grey, connected to the putative membrane spanning helices in black. Pink spheres indicate the location of Sm3+ ions. Reprinted with permission from Lawrence et ah, 1999. Copyright (1999) American Association for the Advancement of Science.

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