what role do cell membranes play in protein synthesis …

The other major model developed for mechanistic studies of endocytosis in focuses on coelomocytes, 6 macrophage-like scavenger cells in the body cavity (pseudocoelom) that are highly active in endocytosis of fluid-phase molecules (). While the natural molecules that are removed from the body cavity by coelomocytes are unknown, coelomocytes are capable of removing many foreign compounds from the body cavity after they are introduced by micro-injection (). The most common of these endocytosis tracers are fluorescently labeled BSA or dextrans. These observations allowed the development of a pulse-chase type assay of coelomocyte endocytosis (). Fluorescently labeled BSA or dextran trafficking through the endosomes of coelomocytes is monitored as a function of time after introduction into the body cavity. Expression of :: GFP is often used to facilitate visualization of endosomes during fluorescent tracer trafficking from the cell surface to the lysosomes ().

Membrane protein synthesis in cell-free systems: From …

The main stages of protein synthesis are transcription and translation.

Membrane phospholipid synthesis and endoplasmic …

Basolateral-specific transport pathways are also thought to play key roles in polarized cells. The best studied of these pathways in is in the transport of the EGF-receptor in the vulval precursor cells (VPCs; see ). is normally restricted to the basolateral membrane of the VPCs, a process that requires the PDZ-domain proteins , , and (). The /7/10 complex binds directly to the intracellular domain, and is therefore likely to function as a sorting factor, directing to the basolateral membrane during secretion and/or after endocytosis and recycling (). The protein has been shown to associate with an intracellular compartment on or near the Golgi consistent with a role in protein sorting during secretion ().

storage, protein synthesis and ..

All of the ectodermal epithelial-like cells are known to require the transcription factor to aquire their final differentiated forms (). In particular it is the apical membrane domain that appear most severely affected in mutant ectodermal epithelia. has therefore been proposed to regulate the expression of gene products that form and maintain apical epithelial character. Screens for mutants with Lin-26-like defects could therefore identify apical-specific trafficking factors. Michaux et al () took just this approach and identified , a predicted 12-pass transmembrane protein required for the function of these cell-types. mutants displayed defects in the hypodermis, excretory canal, vulva, rectum and amphids and phasmids. In mutants vesicles and amorphous material accumulate near the apical surface of the affected cells suggesting that secretion is defective. contains a sterol-sensing domain, a type of domain found in proteins such as Dispatched, Patched and PC1 that are involved in cholesterol associated trafficking processes. A rescuing ::GFP reporter is localized to the apical surface of epithelial cells that require function, consistent with such a proposed function ().

All protein synthesis begins on ribosomes in the cytosol which are unattached to the ER ().
The nucleolus and ribosomes form part of the proteinsynthesizing machinery of the cell

Metabolism: Cell Membrane and Protein Synthesis Essay …

A high-throughput screening of genes that encode proteins transported into the endoplasmic reticulum in mammalian cells. Ozawa T, Nishitani K, Sako Y, Umezawa Y. Nucleic Acids Res. 2005 Feb 24;33(4):e34.

Protein Synthesis


Huber KM, Kayser MS and Bear MF (2000) Role for rapid dendritic protein synthesis in hippocampal mGluR‐dependent long‐term depression. Science 288(5469): 1254–1257.

Maffei L and Berardi N (2002) Protein synthesis in the visual cortex is needed for ocular dominance plasticity. Neuron 34(3): 328–331.

Protein Synthesis | Anatomy and Physiology I

As in other eukaryotes cells possess an endoplasmic reticulum into which most membrane or secretory proteins are inserted co-translationally. Some lumenal ER-resident proteins are retained in the ER by KDEL or HDEL signals in their extreme C-termini. cells also possess Golgi stacks, the next organelle through which secretory proteins pass. Unlike mammalian cells, invertebrates such as have many small "mini stacks" throughout the cytoplasm of most cells rather than one large stack positioned near the nucleus. From the Golgi, secretory proteins and some membrane proteins proceed to either the plasma membrane or to the endosomal system, depending upon various signals embedded in the primary sequence of the proteins. does not possess any obvious homologs of the mannose-6-phosphate receptors, and so may not use the mannose-6-phosphate system for tagging and sorting newly synthesized lysosomal hydrolases. Worms may instead use amino acid based signals and a vps10/sortillin receptor type system for such sorting, as is known to be the case in yeast.