BIOL 1105 Lecture Notes - Lecture 6: Autocrine Signalling, Paracrine Signalling, Tyrosine
14 Nov 2017
School
Department
Course
Professor
Document Summary
Signaling cell releases a signal called a ligand. The target cell uses a receptor to detect signal and initiate a response. This is one of the fastest ways of communication. Gap junctions allow signaling molecules to pass through. This allows cells to function as a whole group. This happens when signaling molecules diffuse through extracellular fluid very short distances. Autocrine signaling: the cell will signal and receive its own signal. This involves nerve cells, neurotransmitters, and synaptic gap. Peptides, proteins, and neurotransmitters are received by external cell surface receptors. Steroids are able to diffuse across the membrane and recognized by an intracellular receptors. Steroid receptors are typically transcription factors and lead to changes in gene expression. Receptors-> effector proteins (enzymes, channel proteins), molecular switches (kinases, g proteins), and second messengers (camp, ca)-> response proteins (enzymes, transcription factors) Phosphorylation (can turn on and off) and dephosphorylation. Depending on the target protein, phosphorylation may either activate or deactivate the protein.
