Cell periphery

Microfibrils are laid down as ribbons having their flat faces parallel to the cell periphery. HemiceUuloses and lignin are deposited between the microfibrils... 

The membrane tubules and lamellae of the endoplasmic reticulum (ER) are extended in the cell with the use of MTs and actin filaments. Kinesin motors are required for stretching out the ER, whereas depolymerization of microtubules causes the retraction of the ER to the cell centre in an actin-dependent manner. Newly synthesized proteins in the ER are moved by dynein motors along MTs to the Golgi complex (GC), where they are modified and packaged. The resulting vesicles move along the MTs to the cell periphery transported by kinesin motors. MTs determine the shape and the position also of the GC. Their depolymerization causes the fragmentation and dispersal of the GC. Dynein motors are required to rebuild the GC. 

The membranes must fill separating functions (gases, methanol, water) and sealing functions (at the cell periphery) in addition to their ionic permselectivity. 

The intracellular environment of eukaryote cells can be subdivided into many regions, including the organelles, nucleus, cytoplasm and the cell periphery. Thus solutes must be delivered to the right intracellular compartment at the correct time to efficiently serve cellular biochemistry. Uncharged solutes such as glucose presumably diffuse across the cell, and the traditional view held until recently was that the major electrolytes, such as Na+,K+,CF and Mg2+, also move around the cell by simple diffusion to eventually arrive at the relevant subcellular compartment by chance. 

When not indicated otherwise, our observations refer to cells in the sub apical area between 300 and 600 pm from the root tip. In the actively growing root, this area is the site of active cell division along with the first stages of cell differentiation, depending on the tissue. Root cells from 2 h-imbibed seeds contained numerous protein bodies19,24 of spheroidal shape, about 1.5-3 pm in diameter and nearly completely filled with highly omiophilic protein material they also contained abundant lipid reserves in the form of minute droplets, mainly concentrated at the cell periphery. The nucleus had spheroid or ellipsoidal shape and showed a distinct nucleolus. The cytoplasm contained numerous mitochondria with a dense matrix as well as relatively small and scarcely differentiated plastids with no or very little starch (Fig. 15.3a,b). 

There was some evidence for the possible involvement of PolyPs localized in the cell periphery in the uptake and phosphorylation of sugars as energy and phosphate donors (Van Steveninck and Booij, 1964 Hofeler et al, 1987). Later, studies of the mechanisms of transport-associated phosphorylation of 2-deoxy-D-glucose in the yeast Kluyveromyces marxianus (Schuddemat et al, 1989b) and Saccharomyces cerevisiae (Schuddemat et al, 1990) resulted in the conclusion that PolyPs seem to replenish the Pj pool and therefore had an indirect role in sugar transport. 

InsP 3R (inositol 1, 4, 5-triphosphate receptor type 2) ER and cell periphery Exogenous expression of tagged protein MDCK cells Yes (Schirmer et al. 2003 Cmttwell et al. 2005)... 

Asano S, Mishima M, Nishida E. Coronin forms a stable dimer through its C-tcrminal coiled coil region an implicated role in its localization to cell periphery. Genes Cells 2001 6 225-35. 

Acanthamoeba 4S4aa, 50kDa, 50% Cytosol, cell periphery, Actin-binding protein... 

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