- 1 What are the characteristics of intermediate filaments?
- 2 Do intermediate filaments have motor proteins?
- 3 Which of the following is the motor protein that intermediate filaments work with?
- 4 Which proteins are found in intermediate filaments?
- 5 What is the main function of intermediate filaments?
- 6 What are two functions of intermediate filaments?
- 7 What are the three domains of a motor protein?
- 8 Is dynein a motor protein?
- 9 Do intermediate filaments need ATP?
- 10 Why are intermediate filaments not used as transport tracks?
- 11 What are the 5 intermediate filaments?
- 12 Are intermediate filaments present in sperm cells?
- 13 What drugs affect intermediate filaments?
- 14 What is general shape of intermediate filaments?
- 15 What is the difference between microfilaments and intermediate filaments?
What are the characteristics of intermediate filaments?
What are some unique features of intermediate filaments?
- IFs are heterogenous.
- IFs lack polarity.
- IFs have a high tensile strength and are resistant to compression, twisting and bending forces.
- IFs lack motor proteins.
- IFs have slower filament dynamics.
Do intermediate filaments have motor proteins?
Intermediate filaments are so named because they are thicker than actin filaments and thinner than microtubules or muscle myosin filaments. As a result, the overall filament has no polarity, and therefore no motor proteins move along intermediate filaments.
Which of the following is the motor protein that intermediate filaments work with?
Although no known motors move on the apolar intermediate filaments, motor proteins move intermediate filaments along microtubules. A spectacular example is found in nerve cells (see Fig. 37.5C).
Which proteins are found in intermediate filaments?
The type IV intermediate filament proteins include the three neurofilament (NF) proteins (designated NF-L, NF-M, and NF-H for light, medium, and heavy, respectively). These proteins form the major intermediate filaments of many types of mature neurons.
What is the main function of intermediate filaments?
Their functions are primarily mechanical and, as a class, intermediate filaments are less dynamic than actin filaments or microtubules. Intermediate filaments commonly work in tandem with microtubules, providing strength and support for the fragile tubulin structures.
What are two functions of intermediate filaments?
Intermediate filaments are therefore found in particularly durable structures such as hair, scales and fingernails. The primary function of intermediate filaments is to create cell cohesion and prevent the acute fracture of epithelial cell sheets under tension.
What are the three domains of a motor protein?
(a) The three major myosin proteins are organized into head, neck, and tail domains, which carry out different functions.
Is dynein a motor protein?
Dynein is one of the three families of cytoskeletal motor protein. Originally identified 50 years ago as an ATPase in Tetrahymena pyriformis cilia3, dynein was named by Gibbons and Rowe after the unit of force, the dyne4.
Do intermediate filaments need ATP?
By using inhibitors of oxidative phosphorylation along with glucose deprivation to lower intracellular ATP levels by 95%, we have found that both stages of intermediate filament collapse require ATP.
Why are intermediate filaments not used as transport tracks?
These motors are capable of transporting IF particles along actin filaments and microtubules in different directions over long distances to specific cellular subdomains. It should be kept in mind, however, that IFs are nonpolar and therefore cannot serve as tracks for unidirectional transport.
What are the 5 intermediate filaments?
Intermediate filaments are distributed in a number of cell types, including: Vimentin in fibroblasts, endothelial cells and leukocytes; desmin in muscle; glial fibrillary acidic factor in astrocytes and other types of glia, and peripherin in peripheral nerve fibers.
Are intermediate filaments present in sperm cells?
Spermatozoa, like many other nucleated cells (77), also appeared to contain intermediate filaments of vimentin type, in contrast to the results of Franke et al.
What drugs affect intermediate filaments?
A number of metabolic inhibitors including the mRNA transcription inhibitor actinomycin D; the protein synthesis inhibitors emetine, cycloheximide, and puromycin; the energy metabolism inhibitors sodium azide and oligomycin; the amino acid analog L-azetidine-2-carboxylic acid; sodium fluoride; and acrylamide each cause
What is general shape of intermediate filaments?
Intermediate Filaments Are Diverse The elementary subunit of the intermediate filaments consists of an elongated rod with an N-terminal “head” and a C-terminal “tail.” A variety of these elementary subunits are made by the body. These associated laterally to form a homo- or heterodimer, approximately 45 nm long.
What is the difference between microfilaments and intermediate filaments?
Microfilaments are often associated with myosin. They provide rigidity and shape to the cell and facilitate cellular movements. Intermediate filaments bear tension and anchor the nucleus and other organelles in place.