Schematic of cell adhesion

The study of cell adhesion is part of cell biology. Cells are often not found in isolation, rather they tend to stick to other cells or non-cellular components of their environment. A fundamental question is: what makes cells sticky? Cell adhesion generally involves protein molecules at the surface of cells, so the study of cell adhesion involves cell adhesion proteins and the molecules that they bind to. Diagram for cell adhesion. ... Diagram for cell adhesion. ... Cell biology (also called cellular biology or cytology, from the Greek kytos, container) is an academic discipline which studies cells. ... Cells in culture, stained for keratin (red) and DNA (green) The cell is the structural and functional unit of all living organisms, sometimes called the building blocks of life. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Cell adhesion molecule - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ...

Cell adhesion proteins (or Cell adhesion molecules, CAMs)

see main article on Cell adhesion molecules

Cell adhesion proteins are often transmembrane receptors. Transmembrane cell adhesion proteins extend across the cell surface membrane and typically have domains that extend into both the extracellular space and the intracellular space. The extracellular domain of a cell adhesion protein can bind to other molecules that might be either on the surface of an adjacent cell (cell-to-cell adhesion) or part of the extracellular matrix (cell-to-ECM adhesion). The molecule that a cell adhesion protein binds to is called its ligand. There are families of cell adhesion proteins that can be characterized in terms of the structure of the adhesion proteins and their ligands. Adhesion between two copies of the same adhesion protein is called "homophilic" binding. Adhesion between an adhesion protein and some other molecule is "heterophilic" binding. Cell adhesion molecule - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Transmembrane receptors are integral membrane proteins, which reside and operate typically within a cells plasma membrane, but also in the membranes of some subcellular compartments and organelles. ... A biological membrane or biomembrane is a membrane which acts as a barrier within or around a cell. ... In biology, extracellular matrix (ECM) is any material part of a tissue that is not part of any cell. ... In chemistry, a ligand is an atom, ion or functional group that is bonded to one or more central atoms or ions, usually metals generally through co-ordinate covalent bond. ...

Cadherins are a class of proteins which are expressed on the surface of cells. ...

Cytoskeletal interactions

For a cell adhesion protein like the one shown in the diagram, the intracellular domain binds to protein components of the cell's cytoskeleton. This allows for very tight adhesion. Without attachment to the cytoskeleton, a cell adhesion protein that is tightly bound to a ligand would be in danger of being ripped out of the fragile cell membrane. Often the connection between the cell adhesion proteins and the cytoskeleton is not as direct as shown in the diagram. For example, cadherin cell adhesion proteins are typically coupled to the cytoskeleton by way of special linking proteins called "catenins". The cytoskeleton is a cellular scaffolding or skeleton contained, as all other organelles, within the cytoplasm. ...

Importance of cell adhesion

Cell adhesion proteins are important for the normal functioning of living organisms. Cell adhesion proteins hold together the components of solid tissues. They are also important for the function of migratory cells like white blood cells. Regulation of cell adhesion proteins is important during embryonic development for the process of morphogenesis. Some people have "blistering diseases" that result from inherited molecular defects in genes for adhesion proteins. Some cancers involve mutations in genes for adhesion proteins that result in abnormal cell-to-cell interactions and tumor growth. Cell adhesion proteins are also important for interactions that allow viruses and bacteria to cause damage to humans. Cell adhesion proteins hold synapses together and the regulation of synaptic adhesion is involved in learning and memory. In Alzheimer's disease there is abnormal regulation of synaptic cell adhesion. Biological tissue is a group of cells that perform a similar function. ... White blood cells (also called leukocytes or immune cells) are a component of blood. ... Developmental biology is the study of the process by which organisms grow and develop. ... Morphogenesis (from the Greek morphê shape and genesis creation) is one of three fundamental aspects of developmental biology along with the control of cell growth and cellular differentiation. ... Three types of viruses: a bacterial virus, otherwise called a bacteriophage (left center); an animal virus (top right); and a retrovirus (bottom right). ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Synapses allow nerve cells to communicate with one another through axons and dendrites, converting electrical signals into chemical ones. ... Memory is a property of the human mind: the ability to retain information. ...

External links

• The Cell (http://www.ncbi.nlm.nih.gov:80/books/bv.fcgi?call=bv.View..ShowSection&rid=cooper.section.2058) by G. Cooper (online textbook)
• Molecular Cell Biology (http://www.ncbi.nlm.nih.gov:80/books/bv.fcgi?call=bv.View..ShowSection&rid=mcb.chapter.6480) by Lodish et al (online textbook)
• Molecular Biology of the Cell (http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Search&db=books&doptcmdl=GenBookHL&term=adhesion+AND+cell%5Bbook%5D+AND+cell%5Bbook%5D+AND+cell%5Bbook%5D+AND+8192%5Buid%5D&rid=cell.section.5121) by Alberts et al (online textbook)
• Cell Adhesion and Extracellular Matrix - The Virtual Library of Biochemistry and Cell Biology (http://www.biochemweb.org/adhesion_ecm.shtml)