BIOL 443 Lecture Notes - Lecture 4: Conformational Change, Stat1, Transcription Factor
Document Summary
Organization of tissues and organs relies on physical properties of the cell, principally differential cell adhesion. Epithelial-epithelial cell interactions are physical and specific. After early embryo cells are dissociated and allowed to reaggregate, cells of the individual germ layers reassociate showing selective affinity within and between layers. The reaggregated germ layers (usually) end up in the correct location. The major class of cell recognition and adhesion is the cadherin. The are transmembrane proteins that form adherens junctions. Anchored by catenin, which provide a connection to the actin cytoskeleton. The type and amount of cadherin determine cell-cell affinity. Allows cells to adhere together: differe(cid:374)t (cid:272)adheri(cid:374)"s ha(cid:448)e differe(cid:374)t affi(cid:374)ities for ea(cid:272)h other, so(cid:373)e of the(cid:373) do (cid:374)ot adhere at all. Allow sheets of epithelial cells to function as a mechanical unit: connection to actin cytoskeleton, movements during gastrulation (tube formation) Cadherin is also a signaling molecule, allowing for changes in gene expression.
