Exam 2 Flashcards
Which of the following types of proteins are likely to have a signal sequence?
-Proteins that are secreted
-Proteins with transmembrane domains
-Proteins destined for the lumen of many organelles
-Two of the above
-All of the above
All of the above
Which of the following amino acid sequences would you expect to find on a protein that gets imported into the nucleus
PKKKRKV
A vesicle budding from the Golgi that is destined for the endoplasmic reticulum would be stimulated by the ___ GTPase and be moving the ___ direction
Arf1; retrograde
Which vesicle coat protein complex would be used for a vesicle made on the Golgi and heading to the ER?
COPI
The kinase domain of tyrosine kinase receptors are on the cytoplasmic side of the plasma membrane and are at the C-terminus of the protein. Thus, you would expect that the C-terminus would be found on the _____ side of the ER membrane immediately following translation, and that it would be on the
_____ side of the membrane of the vesicle that transports it to the plasma membrane.
Cytoplasmic; cytoplasmic
Which protein complex would you expect to be degraded in the transition from metaphase to anaphase?
Cohesin
In COPII coated vesicle formation, which protein(s) is/are a GTPase effector that binds the membrane and recruits the outer coat proteins?
Sec23/24
What is the function of reticulons in the endoplasmic reticulum?
They generate curvature in the ER membrane
Why is the level of cholesterol higher in the Golgi than it is in the ER?
Because cholesterol has a high affinity for sphingolipids that are made in the Golgi
Which family of GTPases is involved in the movement of vesicles from the donor membrane to the acceptor membrane?
Rab
N-linked oligosaccharides involve the covalent linkage of branched polysaccharides to ____ proteins. This takes place on the ____
side of the ER membrane.
in target
asparagine; ER lumen
In which nuclear subdomain would you expect to find rRNA genes being transcribed and the assembly of pre-ribosomal components?
Nucleolus
The proteins Get1/2/3 are involved in which process?
Inserting proteins with C-terminal transmembrane domains into the ER membrane
What is the function of a BAR domain protein?
Induce and stabilize membrane curvature
When Ran enters the nucleus, it rapidly _____ due to the presence of a Ran ____ on the chromatin
Releases GDP; GEF
Which of the following steps in translation uses a GTPase?
1. Initiation
2. Elongation
3. Termination
1,2 and 3
Which of the following occurs once the SRP binds a signal sequence?
-Translation is paused
-The SRP becomes GTP bound and interacts with the SRP receptor
-The ribosome relocates to the endoplasmic reticulum
-the exit pore of the ribosome aligns with the translocon
-all of the above
All of the above
Which of the following is NOT a form of protein acylation used to anchor proteins to a membrane?
Acetylation
Which component of the initiation complex is a major regulatory target to slow or stop mRNA translation?
Elf-2a
A protein that will be secreted ____ have a signal sequence and ___ have a transmembrane domain
Will; will not
The S1P and S2P proteases in the Golgi are involved in which cellular process?
1. Unfolded protein response
2. Regulation of cholesterol synthesis
3. N-linked oligosaccharide addition
1 and 2 only
Which of the following represents the first (i.e. smallest) level of organization of DNA packaging?
-30 nm fiber
-nucleosome
-chromatin fiber
-chromosome
Nucleosome
Which of the following is NOT a function of the endoplasmic reticulum?
-Nuclear compartmentalization
-Lipid signaling and transfer
-Calcium storage and release
-Detoxification of compounds
-Synthesis of cytoplasmic proteins
Synthesis of cytoplasmic proteins
Which of the following is the main regulatory step in the biosynthesis of cholesterol?
-The formation of squalene from two farnesyl groups
-The formation of HMG CoA from Acetyl CoA
-The final (22nd) step that forms mature cholesterol
-The conversion of HMG CoA to Mevalonate
The conversion of HMG CoA to Mevalonate
