Question

In: Biology

synthesis and transport of cell surface protein

synthesis and transport of cell surface protein

Solutions

Expert Solution

Synthesis and transport of cell surface proteins involves a secretory pathway.

Secretory Proteins Move from the Rough ER Lumen through the Golgi Complex and Then to the Cell Surface.

Figure- Outline of the movement of proteins within the secretory pathway.

Ribosomes synthesizing proteins bearing an ER signal sequence become bound to the rough ER. As translation is completed on the ER, the polypeptide chains are inserted into the ER membrane or cross it into the lumen.

Some proteins (e.g., rough ER enzymes or structural proteins) remain resident in the ER.

The remainder move into transport vesicles that fuse together to form new cis-Golgi vesicles. Each cis-Golgi cisterna, with its protein content, physically moves from the cis to the trans face of the Golgi stack.

As this cisternal progression occurs, many luminal and membrane proteins undergo modifications, primarily to attached oligosaccharide chains.

Some proteins remain in the trans-Golgi cisternae, while others move via small vesicles to the cell surface or to lysosomes.

In certain cell types (e.g., nerve cells and pancreatic acinar cells), some soluble proteins are stored in secretory vesicles and are released only after the cell receives an appropriate neural or hormonal signal (regulated secretion).

In all cells, certain proteins move to the cell surface in transport vesicles and are secreted continuously (constitutive secretion).

Like soluble proteins, integral membrane proteins move via transport vesicles from the rough ER to the cis-Golgi and then on to their final destinations.

The orientation of a membrane protein, established when it is inserted into the ER membrane, is retained during all the sorting steps: Some segments always face the cytosol; others always face the exoplasmic space (i.e., the lumen of the ER, Golgi cisternae, and vesicles or the cell exterior).

Retrograde movement via small transport vesicles retrieves ER proteins that migrate to the cis-Golgi and returns them to the ER. Similarly, cis- or medial-Golgi proteins that migrate to a later compartment are retrieved by small retrograde transport vesicles.

Ps- A positive rating would be highly appreciated.

Thanks


Related Solutions

which of the following cell transport mechanism requires a transport protein, but not energy?     A-...
which of the following cell transport mechanism requires a transport protein, but not energy?     A- facilitated diffusion.     B- osmosis     C- active transport.     D- diffusion.     E- secondary active transport.
During the _____ phase of cell reproduction, protein synthesis occurs during the _____ phase of cell...
During the _____ phase of cell reproduction, protein synthesis occurs during the _____ phase of cell reproduction, rapid protein synthesis occurs as the cell grows to double in size. a. G1 :G2 b. S : G2 c. G1 : S d. G2 : S
With explanations, outline the steps involved in the elongation of protein synthesis in a prokaryotic cell.
With explanations, outline the steps involved in the elongation of protein synthesis in a prokaryotic cell.
mtr: tryptophan-specific transport protein – transports tryptophan into the cell trpA: tryptophan synthase, a protein –...
mtr: tryptophan-specific transport protein – transports tryptophan into the cell trpA: tryptophan synthase, a protein – synthesizes tryptophan from its basic components cusF: Periplasmic copper binding protein – binds copper ions tnaA: Tryptophanase – enzyme for tryptophan catabolism trpB: Tryptophan synthase, b protein – synthesizes tryptophan Q. If tryptophan caused the expression level to change, explain why these changes occur for each gene (that is, how does the presence of tryptophan in the media influence expression of the gene...you should...
A cell is LEAST likely to require a transport protein to move which of the following...
A cell is LEAST likely to require a transport protein to move which of the following molecules across its membrane?: (A) Sucrose (B) Hydrogen ions (C) Carbon dioxide (D) Chloride ions
Describe the modes of action of antimicrobial drugs (ie: cell membrane, cell wall, protein synthesis, etc)....
Describe the modes of action of antimicrobial drugs (ie: cell membrane, cell wall, protein synthesis, etc). Please provide an example drug for each. Explain the differences between antibacterial, antifungal, and antiviral drugs. Why is it important to know the difference in the drug targets? Discuss antimicrobial resistance. Be sure to include the mechanisms used by organisms and the implication on treatment options.
What transport mechanism allows water to cross the apical surface of an absorptive cell in the...
What transport mechanism allows water to cross the apical surface of an absorptive cell in the mucosa of the GI tract? Facilitated diffusion Osmosis Primary active transport Secondary active transport Simple diffusion
What is protein synthesis?
What is protein synthesis?
2. Describe the subcellular scheme by which a transmembrane cell surface receptor protein such as the...
2. Describe the subcellular scheme by which a transmembrane cell surface receptor protein such as the platelet derived growth factor receptor gets synthesized and placed at the cell surface. Start with a gene (DNA) but focus primarily on cellular endomembrane systems.
What is the most important transport protein in a plant? What specific cell types is predominant...
What is the most important transport protein in a plant? What specific cell types is predominant in early (Spring) wood? 6.) The Layer of cells that creates root branches is called?.. The structure in question 6 is adjacent to what structure that separates the vascular cylinder from the cortex? thank you so much
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT