BIO 1140 Lecture Notes - Lecture 13: Autocrine Signalling, Paracrine Signalling, Cell Signaling
Document Summary
Direct or juxtacrine signalling may be achieved through channels between adjacent cells. Direct physical contact with other cells or the extracellular matrix (ecm) This type of signalling is particularly important during developmental processes and immune responses. In indirect cell signalling, the signalling molecules are secreted into the cellular environment and will only affect those cells which express the appropriate receptor. This is much like a radio broadcast. This signalling molecules act as a ligand, specifically binding to receptors based on their matching conformations. A cell secretes a signalling molecule which then acts on its own receptors. A cell secretes a signalling molecule which acts as receptors on nearby cells. Growth factors use autocrine and paracrine signalling to coordinate their effects on the cells within their local environment. Cancer cells often exploit these signalling mechanisms to override normal controls, stimulating cell division and cell survival allowing for tumor formation.
