Volk Flashcards
Flashcards for Volk lecture
The nucleus is encased by a two-unit membrane called the ______.
Nuclear Envelope (NE)
The outer membrane of the nuclear envelope is continuous with the ______ system.
endoplasmic reticulum (ER)
The outer membrane of the nuclear envelope is studded with ______, giving it a “rough” appearance.
ribosomes
The inner membrane of the nuclear envelope associates with ______.
heterochromatin
______ are discontinuities in the nuclear envelope that allow for communication between the nucleus and cytoplasm.
Nuclear pores
The ______ is a filamentous meshwork immediately underlying the nuclear envelope.
nuclear lamina
The nuclear lamina is composed of proteins called ______.
lamins
There are approximately ______ nuclear pores per cell.
3000-4000
Nuclear pores have a ______ structure with ______ symmetry.
donut-shaped (also acceptable: basket-shaped); octagonal symmetry
The central channel of a nuclear pore is ______ in diameter.
9 nm
______ contains the genomic DNA in chromosomes.
Chromatin
The nucleolus is a specialized location for the ______ gene component of chromosomes.
rDNA
The nucleolus is visible by both ______ and ______ microscopy.
light and electron
The nucleolus is the site of ______ and ______.
rRNA synthesis, ribosome assembly
______ are distinct regions within the nucleus where transcription occurs.
Transcription factories
______ chromatin associates with interior transcription factories.
Active
______ chromatin is peripherally located at the nuclear envelope.
Heterochromatin
Small molecules, such as proteins less than ______, can pass through nuclear pores by ______.
50 kDa, free diffusion
Larger molecules are actively transported through nuclear pores via interaction with ______.
FG nucleoporins
The nuclear pore complex is composed of ______ proteins.
500-1000
Proteins that function in the nucleus are mostly synthesized in the ______.
cytoplasm
The ______ is a sequence of amino acids that directs proteins into the nucleus.
nuclear localization sequence (NLS)
A common NLS is ______.
-Lys-Lys-Lys-Arg-Lys-
The NLS is both ______ and ______ for nuclear import.
necessary, sufficient
______ is the process by which proteins and RNA are transported out of the nucleus.
Nuclear export
The ______ is a leucine-rich sequence that facilitates nuclear export.
nuclear export sequence (NES)
A consensus NES is ______, where X is any amino acid.
Leu-X1-2-Leu-X2-3-Leu-X-Leu
______ and ______ are chaperone proteins that bind to the NLS or NES.
Importins, exportins
______ is a G protein that regulates nuclear import and export.
Ran
The GTP-bound form of Ran is found in the ______.
cytoplasm
The GDP-bound form of Ran is found in the ______.
nucleus
Ran-GAPs are located in the _______.
cytoplasm
Ran-GEFs are ______-bound.
chromatin
mRNP (mRNA-containing complexes) export is typically a Ran-________ process.
independent
Laminopathies are diseases associated with mutations in ________.
lamin A
Hutchinson-Gilford progeria syndrome (HGPS) is caused by a mutation in _______.
lamin A
HGPS is characterized by a _______ ________ phenotype.
premature aging
Defective nuclear pore function can lead to protein _______, nuclear accumulation of _______ mRNA, and DNA ________.
aggregation, poly-A, damage
Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD) are neurodegenerative diseases linked to ______ mutations.
nuclear pore
Fluorescence In Situ Hybridization (FISH) is a technique used to visualize _________.
specific DNA sequences
_________ can be used to visualize proteins in the nucleus.
Immunofluorescence
_________ is used to determine where on the DNA a particular factor binds.
Chromatin Immuno-Precipitation followed by sequencing (ChIP-seq)
_______ and ______ are variations on ChIP-seq or other NGS techniques used to study the nucleus.
ATACseq, HiCseq
