Posttransition Modification

Question 1

Human proteome

Answer 1

İnsan genomu tarafından üretilen proteinleri gözlemlemek

Question 2

Aminoasit modification-irreversible

Answer 2

Deamidation
Eliminylation

Question 3

Cleavage modification-irreversible

Answer 3

Proteolysis
For example insulin

Question 4

Addition of polypeptides-reversible

Answer 4

Ubiquitiation
UBL-protein conjugation

Question 5

Addition of complex molecules-reversible

Answer 5

AMPylation
ADP-ribosylation
Glycosylation
Prenylation
Lipidation

Question 6

Addition of chemical groups-reversible

Answer 6

Hydroxylation
Phosphorylation
Acetylation
Methylation

Question 7

Protein phosphorylation

Answer 7

Phosphorylation Is performed by enzymes called kinases
Dephosphorylation is performed by phosphatases
p53:tumor suppressor protein

Question 8

Acetylation of histone proteins

Controls chromatin conformation and in turn gene expression

Answer 8

Acetylation of non-Histone proteins such as Tubulin:
Modulates microtubule-dependent Axonal transport and eventually synaptic transmission
Addition of acetyl group
Histen proteininin pozitif yükünü azaltır ve gen okunmasına yardımcı olur
P53 acetylation:growth suppressing properties

Question 9

Protein ubiquitination

Answer 9

Promotes protein degredation through the proteasome
It is important to remove defective or incorrectly folded proteins
**ubiquitin bonds to incorrectly folded proteins and go lysosomes to break down

Question 10

Phosphorylation

Answer 10

Serine,threonine,tyrosine
Cell cycle,apoptosis
Growth
Signal transduction pathway

Question 11

Gylcosylation

Answer 11

Some glycoside group added to protein molecule
—N glycolsylation: bind amino group/asparagine
—O linked:bind hydoxyl ion /serine-threonine
Oligosaccharides
**threonine and serine include hydroxyl group

Question 12

Ubiquitination

Answer 12

26S proteasome tarafından tanınır
Misfolding or defective proteins go to break down after binding with ubiquitin molecules
Addition ubiquitin to lysine residue

Question 13

Ubiquitin proteasome pathway(UPP)

Answer 13

Antigen processing
Apoptosis
Biogenesis of organelles
Cell cycle and division
DNA transcription and repair
Differentiation and development
Immune response and inflammation
Neural and muscular degeneration
Morphogenesis of neural network
Modulation of cell surface
Response to stress and extracellular modulators
Ribosome biogenesis
Viral infection

Question 14

S-nitrosylation

Answer 14

Nitric oxide (NO) is produced by three isoforms of nitric oxide synthase(NOS)
Chemical messenger that reacts with free cysteine residues to form S-nitrothiol(SNOs)
Can kill cancer cells
SNOs protect them from denitrosylation

Question 15

Methylation

Answer 15

Important for histone protein=histones are methylated by KTMs
N-methylation(irreversible)/O-methylation(reversible) (add N or O)
Increase the hydrophobicity
Mediated by methyltransferases
S-adenosyl methionine(SAM) is primary methyl group donor
SAM ,ATP den sonra en çok kullanılan subsrat

Question 16

NAFLD Disease

Answer 16

Metilasyondan kaynaklanır

Question 17

Lipidation

Answer 17

C-terminal glycosyl phosphatidylinositol anchor(GPI)
N-terminal myristoylation
A-myristoylation
S-prenylation(lipid molecule attach protein)

Question 18

GPI anchors

Answer 18

Tether cell surface proteins to plasma membrane
Localized to cholesterol and sphingolipid rich lipid raft which act signaling platform
Reversible:GPI release the protein by phosphoinositol-specific phospholipaseC

Question 19

N- myristoylation

Answer 19

Give proteins a hydrophobic handle for membrane localization
N-myristoyltransferase(NMT)
Uses myristoyl-CoA as substrate
Addition of myristoyl group to glycine residue by an amide bond

Question 20

S-palmitoylation

Answer 20

Used as on/off switch to regulate membrane localization
Palmytoyl group from palmitoyl-CoA to thiolate side chain of cysteine residues via palmitoyl acyltransferases(PATs)
Palmitic acid important for intracellular traffic)
A palmitoyl group is added to cysteine residue

Question 21

Unlike S-palmitoylation ,S-prenylation is hydrolytically stable

Question 22

Prenylation

Answer 22

bir protein veya kimyasal bileşiğe hidrofobik moleküllerin eklenmesidir.
Addition of isoprenoid moiety to cysteine residue

Question 23

Hydroxylation

Answer 23

Add hydroxyl group
Catalyzed by enzymes termed as hydroxylases
Aid in converting hydrophobic or lipophilic compounds into hydrophilic compound
Important for collagen bipsynthesis white cell production in our cells

Question 24

AMPylation

Answer 24

Formation phosphodiester bond

Question 25

Proteolysis

Answer 25

Breakdown protein into small polypeptides or aa
Insulin needs proteolysis reaction

Question 26

Deamination

Answer 26

Removal or conversion of aspargine or glutamine residue to another functional group