Intermediate Filaments (Campbell Biology)
Intermediate filaments are named for their diameter, which is larger than the diameter of microfilaments but smaller than that of microtubules (see Table 6.1). While microtubules and microfilaments are found in all eukaryotic cells, intermediate filaments are only found in the cells of some animals, including vertebrates. Specialized for bearing tension (like microfilaments), intermediate filaments are a diverse class of cytoskeletal elements. Each type is constructed from a particular molecular subunit belonging to a family of proteins whose members include the keratins. Microtubules and microfilaments, in contrast, are consistent in diameter and composition in all eukaryotic cells.
Intermediate filaments are more permanent fixtures of cells than are microfilaments and microtubules, which are often disassembled and reassembled in various parts of a cell. Even after cells die, intermediate filament networks often persist; for example, the outer layer of our skin consists of dead skin cells full of keratin filaments. Chemical treatments that remove microfilaments and microtubules from the cytoplasm of living cells leave a web of intermediate filaments that retains its original shape. Such experiments suggest that intermediate filaments are especially sturdy and that they play an important role in reinforcing the shape of a cell and fixing the position of certain organelles. For instance, the nucleus typically sits within a cage made of intermediate filaments, fixed in location by branches of the filaments that extend into the cytoplasm. Other intermediate filaments make up the nuclear lamina, which lines the interior of the nuclear envelope (see Figure 6.9). By supporting a cell’s shape, intermediate filaments help the cell carry out its specific function. For example, the network of intermediate filaments shown in Figure 6.25 anchors the microfilaments supporting the intestinal microvilli. Thus, the various kinds of intermediate filaments may function together as the permanent framework of the entire cell.
Urry, Lisa A.. Campbell Biology. Pearson Education. Kindle Edition. https://www.pearson.com/us/higher-education/series/Campbell-Biology-Series/2244849.html
Date Published: August 12, 2010 Publisher: Public Library of Science Author(s): Robert Kirmse, Zhao Qin, Carl M. Weinert, Andrea Hoenger, Markus J. Buehler, Laurent Kreplak, Vladimir N. Uversky. http://doi.org/10.1371/journal.pone.0012115 Abstract: Intermediate filaments (IFs) assembled in vitro from recombinantly expressed proteins have a diameter of 8–12 nm and can reach several micrometers in length. IFs assemble from … Continue reading
Date Published: January 25, 2016 Publisher: Public Library of Science Author(s): Hyunook Kang, Thomas M. Weiss, Injin Bang, William I. Weis, Hee-Jung Choi, Petri Kursula. http://doi.org/10.1371/journal.pone.0147641 Abstract: Desmoplakin (DP) is a cytoskeletal linker protein that connects the desmosomal cadherin/plakoglobin/plakophilin complex to intermediate filaments (IFs). The C-terminal region of DP (DPCT) mediates IF binding, and contains … Continue reading
Date Published: June 15, 2012 Publisher: Public Library of Science Author(s): Boris Grin, Saleemulla Mahammad, Tatjana Wedig, Megan M. Cleland, Lester Tsai, Harald Herrmann, Robert D. Goldman, Laurent Kreplak. http://doi.org/10.1371/journal.pone.0039065 Abstract: Withaferin A (WFA) is a steroidal lactone present in Withania somnifera which has been shown in vitro to bind to the intermediate filament protein, vimentin. … Continue reading
Date Published: July 3, 2013 Publisher: Public Library of Science Author(s): Bruno Pontes, Yareni Ayala, Anna Carolina C. Fonseca, Luciana F. Romão, Racκele F. Amaral, Leonardo T. Salgado, Flavia R. Lima, Marcos Farina, Nathan B. Viana, Vivaldo Moura-Neto, H. Moysés Nussenzveig, Stefan FT. Weiss. http://doi.org/10.1371/journal.pone.0067708 Abstract: Recent studies indicate that the cell membrane, interacting with … Continue reading
Date Published: October 30, 2015 Publisher: Public Library of Science Author(s): Serge Dmitrieff, François Nédélec, Helge Ewers Abstract: Endocytosis is an essential process by which cells internalize a piece of plasma membrane and material from the outside. In cells with turgor, pressure opposes membrane deformations, and increases the amount of force that has to be … Continue reading
Research Article: Cell Membrane Disruption Stimulates NO/PKG Signaling and Potentiates Cell Membrane Repair in Neighboring Cells
Date Published: August 7, 2012 Publisher: Public Library of Science Author(s): Tatsuru Togo, Paul McNeil. http://doi.org/10.1371/journal.pone.0042885 Abstract: Resealing of a disrupted plasma membrane at the micron-diameter range requires Ca2+-regulated exocytosis. Repeated membrane disruptions reseal more quickly than the initial wound, and this potentiation of membrane resealing persists for at least 24 hours after the initial wound. … Continue reading
Research Article: Tamiflu-Resistant but HA-Mediated Cell-to-Cell Transmission through Apical Membranes of Cell-Associated Influenza Viruses
Date Published: November 30, 2011 Publisher: Public Library of Science Author(s): Kotaro Mori, Takahiro Haruyama, Kyosuke Nagata, Ron A. M. Fouchier. http://doi.org/10.1371/journal.pone.0028178 Abstract: The infection of viruses to a neighboring cell is considered to be beneficial in terms of evasion from host anti-virus defense systems. There are two pathways for viral infection to “right next door”: … Continue reading