How are proteins targeted to their destination?
How are proteins targeted to their destination?
Proteins are shipped to other destinations if they contain the right molecular labels. For example, proteins destined for the lysosome have a molecular tag consisting of a sugar with a phosphate group attached. In the Golgi apparatus, proteins with this tag are sorted into vesicles bound for the lysosome.
How are proteins targeted to the nucleus?
Proteins destined for the nucleus contain NLSs. These short stretches of amino acids interact with proteins located in the cytoplasm, on the nuclear envelope, and/or at the nuclear pore complex. Following binding at the pore complex, proteins are translocated through the pore into the nucleus in a manner requiring ATP.
What are targets by proteins in the ER?
Proteins destined for secretion or incorporation into the ER, Golgi apparatus, lysosomes, or plasma membrane are initially targeted to the ER. In mammalian cells, most proteins are transferred into the ER while they are being translated on membrane-bound ribosomes (Figure 9.3).
How and why are proteins targeted to specific cellular locations?
Some cytoplasmic proteins are targeted to a particular site in the cell because they contain a specific amino acid sequence that causes them to bind to receptors located at that site. This sequence of amino acids allows a protein possessing it to bind to nuclear localization receptors found in the nucleus .
What is the first step in protein targeting?
translocation to
Explanation: The first step in protein targeting is its translocation to the ER after its production from the ribosome. Only after this translocation proteolytic cleavage occurs producing the mature protein which undergoes many modifications before it is targeted to its destination.
Which of the following statements correctly describes the targeting of proteins to the mitochondrial matrix or the nucleus?
Which of the following statements correctly describes the targeting of proteins to the mitochondrial matrix or the nucleus? Proteins targeted to the mitochondrial matrix are unfolded while being inserted into the mitochondria and are refolded within the matrix.
How are proteins transported around the cell?
From the endoplasmic reticulum, proteins are transported in vesicles to the Golgi apparatus, where they are further processed and sorted for transport to lysosomes, the plasma membrane, or secretion from the cell.
How are proteins targeted into the eukaryotic secretory pathway?
The secretory pathway occurs in a vectorial manner and begins with uptake of amino acids that are used by the rough endoplasmic reticulum to produce newly synthesized proteins. These new proteins are transported to the Golgi complex for further processing and sorting.
What is the Golgi apparatus function?
A Golgi body, also known as a Golgi apparatus, is a cell organelle that helps process and package proteins and lipid molecules, especially proteins destined to be exported from the cell.
Where do proteins go when they leave the cell?
Protein cargo moves from the ER to the Golgi, is modified within the Golgi, and is then sent to various destinations in the cell, including the lysosomes and the cell surface. The Golgi processes proteins made by the endoplasmic reticulum (ER) before sending them out to the cell.
What is specificprotein targeting and why is it important?
Protein targeting refers to the methods cells use to get proteins to the proper location after synthesis. Proteins play a major role in most cellular processes but must be located properly to serve their functions. Knowing how newly synthesized proteins target within cells is essential for understanding protein function.
What is protein targeting or protein sorting?
Sign up for a Scribd free trial to download now. Protein targeting or protein sorting is the mechanism by which a cell transports to the appropriate positions in the cell or outside of it.
Why are cytoplasmic proteins targeted to a specific site in the cell?
Some cytoplasmic proteins are targeted to a particular site in the cell because they contain a specific amino acid sequence that causes them to bind to receptors located at that site.
How are proteins targeted to the ER after they are synthesized?
Targeting of proteins to the ER begins before the polypeptide chain is completely synthesized. This is in contrast to import of proteins to mitochondria, chloroplasts, and peroxisomes, which occurs after synthesis is completed. An ER signal peptide, localized at the amino terminus of these proteins,…
