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Effect of cytoarchitecture on the transport and localization of protein synthetic machinery
Author(s) -
LubyPhelps Katherine
Publication year - 1993
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240520205
Subject(s) - cytoplasm , microbiology and biotechnology , cytoarchitecture , endoplasmic reticulum , biology , cytoskeleton , filamin , microtubule , organelle , polysome , ribosome , nucleus , transport protein , biochemistry , cell , anatomy , rna , gene
The emerging picture of cytoarchitecture imposes constraints on the transport and localization of several components of the protein synthetic machinery. The range in which “free” polysomes can diffuse through the cytoplasm may be restricted to about 50 nm due to obstruction by cytoskeletal barriers. Individual ribosomes and large transcripts will diffuse at least 4–10 times slower in cytoplasm than in dilute aqueous solution and may be sterically excluded from some cytoplasmic domains. The transport of these components from the nucleus to the cell periphery may be restricted to microtubule‐containing channels that traverse the excluding domains. In the peripheral cytoplasm, mitochondria, endoplasmic reticulum, and other membrane‐bound organelles are found only in nonexcluding channels, while actin, nonmuscle filamin (ABP280), and fodrin are concentrated in excluding domains. This suggests that the cytoplasmic volume may be functionally compartmentalized by local differentiations of cytoarchitecture. Excluding compartments may play a structural role, while nonexcluding compartments are the site of vesicle traffic and protein synthesis.