○ N-acety-gu 25.2 Oligosaccharides ● Mannose● Glucose are added to proteins in Dolich the er and golgi Glycosyl transferase ENDOPLASMIC RETICULUM Figure 25.3 An oligosaccharide is formed on dolichol and Ho- CHo-CANt Asparagine in target c=o: t transferred by glycosyl transferase to asparagine of a target protein = 消当 Glycoprotein
Figure 25.3 An oligosaccharide is formed on dolichol and transferred by glycosyl transferase to asparagine of a target protein. 25.2 Oligosaccharides are added to proteins in the ER and Golgi
○N-acet/ glucosamine ● Mannose● Glucose 25.2 Oligosaccharides are added to proteins in the ER and golgi ●●鲁 Figure 25.4 Sugars are R glucosidases|&‖ removed in the er in a fixed NH order, initially comprising 3 H HC-CH2○鲁● glucose and 1-4 mannose residues. This trimming ↓ ER mannosidase generates a high mannose oligosaccharide. High mannose c2c○○ oligosaccharide 消当
Figure 25.4 Sugars are removed in the ER in a fixed order, initially comprising 3 glucose and 1-4 mannose residues. This trimming generates a high mannose oligosaccharide. 25.2 Oligosaccharides are added to proteins in the ER and Golgi
Golgi mannosidase 25.2 Oligosaccharides are added to proteins in the er and Golgi ↓ N-acetyl- glucosamine transfe rase Figure 25.5 Processing for a complex oligosaccharide occurs in the Golgi and trims the original preformed unit to the ↓ Golgi manno sida se‖ inner core consisting of 2 N-acetyl glucosamine and 3 mannose residues HC H resistance Then further sugars can be added, in the order in which the transfer enzymes are Golgi enzymes add further encountered to generate a terminal residues Galsialic acid region containing N-acetyl-glucosamine HC-CH galactose, and sialic acid winner core Terminal region 消当
Figure 25.5 Processing for a complex oligosaccharide occurs in the Golgi and trims the original preformed unit to the inner core consisting of 2 N-acetylglucosamine and 3 mannose residues. Then further sugars can be added, in the order in which the transfer enzymes are encountered, to generate a terminal region containing N-acetyl-glucosamine, galactose, and sialic acid. 25.2 Oligosaccharides are added to proteins in the ER and Golgi
25.2 Oligosaccharides are added to proteins in the er and golgi 含2 Figure 25. 6 The golgi apparatus consists of a series of individual membrane stacks Photograph kindl provide d by alain Rambourg 消当
Figure 25.6 The Golgi apparatus consists of a series of individual membrane stacks. Photograph kindly provided by Alain Rambourg. 25.2 Oligosaccharides are added to proteins in the ER and Golgi
25.2 Oligosaccharides are added to proteins in the er and golgi 句f mannose-6-P receptors sialyl transferase Figure 25. 7 A Golgi acid phosphatase stack consists of a series galacto sy tran sferase F rans cistern of cisternae organized with cis to trans polarity 1P-NAc-qlucosaminidase NADPase mediakeisterna Protein modifications mannosidase‖l occur in order as a gIcN-acetyl-transferase mannosidase I as cisterna protein moves from the Golgi: c isease cis face to the trans face 消当
Figure 25.7 A Golgi stack consists of a series of cisternae, organized with cis to trans polarity. Protein modifications occur in order as a protein moves from the cis face to the trans face. 25.2 Oligosaccharides are added to proteins in the ER and Golgi