This topic delves deeper into the cell and explores what lies between the plasma membrane and the nucleus. The focus is on the three cytoskeletal systems – what is on the surface and what is inside.
3.1 Actin Filaments: This section introduces three cytoskeletal filament systems: Actin filament, microtubules, and intermediate filament. These systems have numerous associated proteins that regulate and organize the network and are referred to as cytoskeletal systems since they are made of many proteins.
● Actin Monomers: Structure and Polarity
● Actin Filaments: Assembly/Disassembly
● Geography of Actin Filaments Within a Cell
● Organizing the Actin Filament Network
● How Does Myosin I Function as a Molecular Motor Protein?
● Myosin II: Structure
● Myosin II: A Technological Tool
● Actin Monomers—Structure and Polarity
3.2 Microtubules: This module introduces microtubules, one of the three cytoskeletal systems in the cell. The properties regulating this system will be described as well as its geographical significance within the cell.
● Microtubule: Structure and Polarity
● Microtubule Assembly/Disassembly
● Geography of Microtubules Within a Cell
● Specialized Microtubule-Based Structures
● Microtubule Network-Associated Proteins
● Visualization of Microtubular Polarity
3.3 Intermediate Filaments: Intermediate filaments with associated proteins are one of the three cytoskeletal systems present in eukaryotic cells. Intermediate filaments are different from the other two cytoskeletal systems (i.e.,the actin and microtubule systems), which will be explained in this module.
● Intermediate Filaments: Structure and Polarity
● Intermediate Filaments: Assembly
● Geography of Intermediate Filaments Within a Cell
● Nuclear Lamina
● Intermediate Filament-Associated Proteins
● Intermediate Filaments: The Strongest
● Resistance to Mechanical Stress
● Delayed Biochemical Confirmation?
3.4 Intercellular Junctions: Epithelial tissue has the unique role of extending the function of biological membranes over large sheets of cell (i.e., tissues). The special proteins causing this are discussed in this module.
● Epithelial Cells: Cells that Do Not Walk
● Tight Junctions: Creating a Physical Barrier
● Adhering/Anchoring Junctions; Strengthening Tight Junctions
● Lack of Communication
● Gap Junctions: Communicating Junctions
● The Anastomosing Layer—Tight Junction vs Adhering Junction
3.5 Cell Fractionation: In this module, we will compare the processes, tools, and chemicals involved in cell fractionation across two different methods: 1) a classic approach that separates the nuclear and cytoplasmic fraction and 2) an approach that separates the cell into cytoskeletal and soluble fractions.
● Nuclear and Cytoplasmic Fractionation
● Cytoskeletal and Soluble Fractionation
● Homogenization Buffer—Components, Purpose, and Temperature