Lecture 11 Flashcards
(13 cards)
For proteins destined for secretion out of the cell, they are synthesized in the RER, and there is a length of about 20-30 _____ AAs that bind the SRP in the cytosol. Translation is stalled until the SRP binds its receptor on the RER. In this way, protein translocation into the RER is __-______.
Hydrophobic
Co-translational
Protein destinations are determined by their __-terminus signals. Those destined for the ER membrane have a ___ signal. Those destined for lysosomal enzymes have a ___-__-____. Those destiend for secretion out of the cell are the default. Note: ___-cell disease is due to a genetic defect in adding the lysosomal enzyme signal, leading to characteristic ___ bodies in the cell.
N-terminus
Halt
Mannose-6-phosphate
I-cell disease
Inclusion bodies
______ syndrome arises from defects in genes required for peroxisomal targeting or function.
Zellweger syndrome
Proteins destined for the ______ have an __-terminus leader of about 20-80 charged AAs.
Note: Several hundred mitochondrial proteins are made in the cytosol from nuclear-encoded mRNA. The mitochondrial genomre encodes about 13 proteins chiefly used in the _____ _____ _____.
Mitochondria
N-terminus
Electron Transport Chain
_____ disease, multiple sulfatase deficiency, combines features of several ____ diseases. The primary defect is in sulfatase-modifying factor 1 (SUMF1), which is required to modify an essential _____ (AA) in the active site of sulfatases.
Austin disease (Austin “sulfered” with awkward bones and lost his abilities by age one.)
Lysosomal
Cysteine
Ehlers-Danlos syndrome type VI arises from a genetic disorder in ____ _____ 1, which leads to unmodified collagen.
Lysyl hydroxylase 1
_____ disease is a result of selenium deficiency. In parts of China where the soil is sparse in selenium, the food grown there is also sparse in it. Symptoms include large fatty _____ (as well as congestive _____ failure), striated muscle degeneration, and weakness.
Keshan disease
Heart
Heart
Selenium is present in the body as selenocysteine in selenoproteins. Selenocysteine is incorporated into peptides via recognition of the ____ element in the 3’ UTR of an mRNA molecule, subsequent binding to SBP2 which interacts with a specialized elongation factor _____ that articulates with SeCys-tRNA (converted from ___-tRNA) and what normally would be a _____ codon in the mRNA. These proteins catalyze _____ reactions.
SECIS element
eEFSec
Ser-tRNA
Stop (UGA specifically)
Redox
________ peroxidases are an example of selenoproteins that protect against oxidative damage.
Glutathione peroxidases
5’-_______ are also an examples of selenoproteins that convert thyroxine to ____ (the more active form) by removing _____ from the outer ring, but can inactivate either thyroid hormone by removing an ____ from the inner ring.
5’-deiodinases
T3
Iodine
Iodine
Vitamin ____ is required for blood clotting (“koagulation”) as a coenzyme. It catalyzes a ___-______ reaction of glutamate in proteins. This allows for chelation of _____.
Vitamin K
gamma-carboxylation
Ca++
______ (_____ - the trade name) is an anticoagulant that blocks the modification of 4 clotting factors and blocks NADPH-dependent vit ____ recycling.
Vitamin K recycling
Protein _____ is an non-enzymatic reaction that occurs at the N-terminus alpha-NH2 and internal lysine ___-NH2. It is associated with diabetes pathogenesis, and is clinically measured via ____, a modified and electrophoretically distinct hemaglobin as a result of this reaction. Normal hemaglobin is ______ on the N-terminus _____ (AA) of hemaglobin ____- chains. Measurement of _____ shows the time-averaged blood glucose levels over the preceding ___-___ weeks (number of weeks).
Glycation
Epsilon
HbA1c
Glycated
Valine
Beta-chains
HbA1c
3-6
