BIOL 1090 Lecture Notes - Lecture 26: Golgi Apparatus, Oligosaccharide, Spectrin
18 Jan 2017
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Document Summary
Proteins are modified step-wise as they travel through the golgi. Different cisternae of golgi contain different enzymes that modify proteins. Proteins with n-linked oligosaccharides arrive form er. O-linked oligosaccharides are modified entirely in the golgi. As oligosaccharide moves through the cis to trans stacks it gets modified through the action of integral membrane proteins whose active sites face the lumen of the golgi cisternae. Smooth, flattened, disk-like cisternae (~0. 5-1 micron in diameter) Shows polarity: neg: cis-medial-trans cisternae, pos: cisternae are biochemically unique. Membrane supported by protein skeleton (actin, spectrin) Scaffold linked to motor proteins that direct movement of vesicles into and out of golgi. Modification of proteins and lipids: glycosylation (glycoproteins and glycolipids, proteolytic modification. Cgn: (cid:862)sorting station(cid:863), sorts whether proteins should continue on to next golgi station or be shipped back to the er. Tgn: sorts proteins into different types of vesicles which o to plasma membrane or other intracellular destinations.
