What does tunicamycin do to cells?
What does tunicamycin do to cells?
Tunicamycin blocks N-linked glycosylation (N-glycans) and treatment of cultured human cells with tunicamycin causes cell cycle arrest in G1 phase. It is used as an experimental tool in biology, e.g. to induce unfolded protein response.
Where are things glycosylated?
Glycosylation of proteins and lipids occurs in the endoplasmic reticulum (ER) and Golgi apparatus, with most of the terminal processing occurring in the cis-, medial- and trans-Golgi compartments.
Can phospholipids be glycosylated?
Glycosidated phospholipids, are a novel class of alkylphospholipids, in which carbohydrates or carbohydrate-related molecules are introduced in the chemical lead of PAF. These hybrid alkylphospholipids also exhibit anti-proliferative capacity.
Which amino acid inhibits glycosylation?
Tunicamycin inhibits N-glycosylation in eukaryotes by blocking the transfer of N-acetylglucosamine-1-phosphate (GlcNAc-1-P) from UDP-GlcNAc to dolichol-P (catalyzed by GlcNAc phosphotransferase; GPT), thereby decreasing the formation of dolichol-PP-GlcNAc (Chapter 9).
How does Tunicamycin induce UPR?
Tunicamycin (Tun), a naturally occurring antibiotic, induces ER stress in cells by inhibiting the first step in the biosynthesis of N-linked glycans in the proteins resulting many misfolded proteins .
What is the function of Dolichol?
Functions. Dolichols play a role in the co-translational modification of proteins known as N-glycosylation in the form of dolichol phosphate. Dolichols function as a membrane anchor for the formation of the oligosaccharide Glc3-Man9-GlcNAc2 (where Glc is glucose, Man is mannose, and GlcNAc is N-acetylglucosamine).
What is the difference between N and O glycosylation?
The key difference between N glycosylation and O glycosylation is that N glycosylation occurs in asparagine residues whereas O glycosylation occurs in the side chain of serine or threonine residues.
Is insulin glycosylated?
These glycosylated insulin molecules are reversibly bound to the glucose-binding lectin Concanavalin A (Con A). Such sugar-insulin/lectin complexes serve as an insulin reservoir from which sugar-insulin molecules are displaced by glucose.
What is N and O linked glycosylation?
Other major differences in the two types of glycosylation are (1) N-linked glycosylation occurs on asparagine (N) residues within an N-X-S or N-X-T sequence (X is any amino acid other than P or D) while O-linked glycosylation occurs on the side chain hydroxyl oxygen of either serine or threonine residues determined not …
Where does O-linked glycosylation occur?
O-glycosylation is a post-translational modification that occurs after the protein has been synthesised. In eukaryotes, it occurs in the endoplasmic reticulum, Golgi apparatus and occasionally in the cytoplasm; in prokaryotes, it occurs in the cytoplasm.
Which of the amino acid participate in O glycosylation?
In O-linked glycosylation the carbohydrate moiety is covalently linked to the hydroxyl oxygen of the hydroxyamino acids serine and threonine. In addition, O-glycosylation also occurs as a primary modification of tyrosine and as a secondary modification of 5-hydroxylysine and 4-hydroxyproline.
Is Calnexin a transmembrane?
Calnexin is a transmembrane protein and calreticulin is the soluble luminal homolog. Both proteins interact with monoglucosylated, trimmed intermediates of N-linked core glycans on nascent glycoproteins.