BIOL 205 Lecture Notes - Lecture 28: Cytosol, Protein Aggregation, Clathrin
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No environmental signals required for vesicle fusion with the plasma membrane. Ex) secretion of proteins of cell wall (in plants/fungi) / Only in cells that are specialized for secretion (this is in addition to constitutive secretion in these cells). Proteins destined for the regulated secretory pathway are stored in secretory vesicles for later release. Vesicles are only released when a specific signal is received (binding of hormone, action potential, etc. ) Examples: digestive enzymes, insulin, steroid hormones, peptide hormones, neurotransmitters, etc. Purpose: secretion of proteins rapidly and on demand. Ex) insulin secretion (regulated by blood sugar levels) Gfp-tagging proteins tracked in living cell by fluorescence microscopy or stain/mark the protein to follow with radio label. Before experiment begins, proteins are being synthesized at steady state though the translation of mrna by ribosomes. The pulse: large dose of radioactive amino acids is added for a brief period. Radioactive amino acids are incorporated into the proteins.