Exam 3 Key Experiments and Molecular Medicine Flashcards
Families with non-sex linked Emery-Dreifuss muscular dystrophy had mutations in the single gene (___) encoding nuclear lamins A and C.
LMNA
Two hypotheses for how mutations in nuclear lamins cause different tissue-specific diseases:
One is the ___ ___ hypothesis that posits the correct interaction of lamin A and C with the nuclear envelope is essential for normal tissue-specific expression of certain genes.
gene expression
Two hypotheses for how mutations in nuclear lamins cause different tissue-specific diseases:
The other is the ___ ___ hypothesis that states the mutations in the nuclear lamin-emerin complex weaken the structural integrity of an integrated cytoskeleton network.
mechanical stress
The viral protein ___ ___ ___ was used as a model of study for finding nuclear localization signals in animal cells.
SV40 T antigen
By deleting/replacing single amino acids in the peptide chains of T antigen, they found that the amino acid sequence from residue ___ to ___ served as a nuclear localization signal.
127 to 132
In vitro translation of light-chain mRNA on free ribosomes yielded a protein that was ___ than the secreted light chain.
larger
Results indicated that a(n) ___ ___ ___ is removed by a microsomal protease as growing polypeptide chains are transferred across the membrane.
amino-terminal signal sequence
Thanks to the discovery of amino-terminal signal sequences, cell biologists have a better understanding of how all ___ are transferred across membrane-encolosed compartments in the cell.
proteins
___ disease is the most common of lysosomal storage diseases, which are caused by a failure of lysosomes to degrade substances that they would normally break down.
Gaucher disease
Gaucher disease is caused by a deficiency of the lysosomal enzyme ___ which catalyzes the hydrolysis of glucosylceramide to glucose and ceramide.
glucocerebrosidase
The only cells affected by Type 1 Gaucher disease are ___.
macrophages
A mutation in mitochondrial DNA causes LHON: The mutation affects one of the subunits of ___ ___ of the ETC.
complex 1 (NADH dehydrogenase)
LHON:
This mutation in mitochondria affects cells which rely on oxidative phosphorylation the most, primarily cells in the ___.
CNS (Central Nervous System)
Peroxisome biogenesis disorders result from mutations in the ___ proteins responsible for peroxisome assembly.
Pex proteins
A microtubule experiment identified a 110-kd polypeptide that was bound to microtubules in the presence of AMP-PNP, and released by subsequent incubation with ATP -> named ___.
kinesin
Kinesin is a protein responsible for the movement of ___ along microtubules (in the plus-end direction).
organelles
The expression of mutant ___ causes abnormal skin development.
keratin
The skin abnormalities of transgenic mice provided the first direct support of the presumed role that keratins help provide ___ ___ to epithelial cells in tissues.
mechanical strength
Primers were used to amplify mRNAs of olfactory neurons by reverse transcription, followed by PCR. After PCR, they conducted nucleotide sequencing of 10 cDNA clones. These particular complete clones showed that they encoded a distinct family of proteins with the ___ transmembrane a helices characteristic of ___ ___ ___.
7, g protein-coupled receptors
Cancers can result from the action of specific genes (___).
oncogenes
Mutated ___ oncogenes are found in about 25% of all human cancers, including 25% of lung cancers, 50% of colon cancers, and more than 90% of pancreatic cancers.
ras
The oncogenic Ras proteins remain in the GTP-bound state, continuously stimulating the ___ pathway to drive cell proliferation.
ERK
