Cytoskeleton Flashcards
determine the shape of the cell’s surface and are necessary for whole-cell locomotion
form many types of cell-surface projections like lamellipodia and filopodia that cells use to explore territory and move around
actin filaments
determine the positions of membrane-enclosed organelles, direct intracellular transport, and form the mitotic spindle that segregates chromosomes during cell division
form cilia, which function as motile whips or sensory devices on the surface of the cell
can quickly rearrange themselves to form a bipolar mitotic spindle during cell division
Microtubules
What is the monomer of actin filament?
actin
What is the monomer of microtubules?
tubulin
provide mechanical strength
line the inner face of the nuclear envelope, forming a protective cage for the cell’s DNA
intermediate filaments
hold epithelial cell sheets together or help nerve cells to extend long and robust axons, and they allow us to form tough appendages such as hair and fingernails
intermediate filaments
another word for actin subunits
Globular (G) - actin
homolog of tubulin:
which can polymerize into filaments and assemble into a ring; important for cell division and cell fission
FtsZ
homologs of actin:
assemble to form dynamic patches that move circumferentially along the length of the cell; contribute to cell shape by serving as a scaffold to direct the synthesis of the peptidoglycan cell wall
MreB and Mbl
Bacterial homologs of actin:
carry genes responsible for antibiotic resistance and cause the spread of multidrug resistance in epidemics; and ParR proteins important for segregation
ParM
Combination of end-to-end are seen in _____ and ____
actin and microtubule
combination of subunit in side-to-side are seen in ______
intermediate filaments
What type of actin are expressed only in muscle cells?
α-Actin
β- and γ-actins are found together in almost all _____
non- muscle cells
What do you call to the slower-growing end of the actin filament?
minus end or pointed end
What do you call to the faster-growing end of the actin filament?
plus end or barbed end
what do you call to the aggregation of 3 actin subunit to start the elongation?
nucleus
What happens in nucleation process?
actin monomers forming 3 (nucleus)
What happens in actin polymerization process?
elongation of actin filament
What happens in actin treadmilling?
elongation at the same time some loose in the negative end
are fungal products that prevent actin polymerization by binding to the plus end of actin filaments.
Cytochalasins
prevents actin polymerization by binding to actin subunits.
Latrunculin
toxins isolated from the Amanita mushroom that bind tightly all along the side of actin filaments and stabilize them against depolymerization
Phalloidins
prevent the actin filament from interacting with other proteins
important in the control of muscle contraction
Tropomyosin