Diseases and protein modifications Flashcards
List the different types of protein modification
- Hydroxylation of proline
- Carboxylation of glutamate
- Glycosylation
- Acetylation/methylation
- Reversible phosphorylation/dephosphorylation
- Ubiquitination
What causes hemorrhage?
Vitamin K deficiency, resulting in gamma glutamyl carboxylase not working properly
Reversible phosphorylation/dephosphorylation typically occurs at what amino acids?
Ser, Thr, Tyr
What does Vitamin C deficiency result in? What disease results?
loss in prolyl hydroxylase = no proline hydroxylation = scurvy
What does ubiquitination do to a protein?
Marks it for degredation by proteosome
What enzyme is used to make hydroxyproline?
prolyl hydroxylase
What important molecules require the carboxylation of glutamate?
clotting factors (II, VII, IX, X ect)
Name two types of glycosylation
O-linked, N-linked
What residue gets acetylated by HATS?
Lysine residues on Histones
What enzyme gets targeted/prevented to treat Chronic myelogenous leukemia (CML)?
bcr-abl tyrosine kinase
Vitamin K deficiency will lead to what?
Hemorrage. (Vit K is needed for gamma-glutamyl carboxylase)
O-linked glycosylation occurs on which amino acids?
Ser (S) and Thr (T)
What enzyme is used for the carboxylation of glutamate?
gamma-glutamyl carboxylase
Where does gamma-glutamyl carboxylase attach the carboxyl group on glutamate?
The the R side chain of glutamate
What amino acid residues does ubiquitin usually get added to?
Lys
hydroxyprolines are the predominant secondary structure in what structure?
Collagen
Vitamin C is a necessary cofactor for what enzyme?
Prolyl hydroxylase
What is the most common protein modification in the cell?
Ubiquitination
Mutation in N-linked glycosylation can lead to which disorder?
Congenital Disorder of Glycosylation (CDG)
Gamma-glutamyl hydroxylase depends on what cofactor to function?
Vitamin K
N-linked glycosylation usually involve sugars binding to which amino acids?
Asn
Congenital Disorder of glycosylation involve what symptoms?
Developmental delay, hypertonia
Briefly describe how you can get scurvy
Vitamin C deficiency -> loss in prolyl hydroxylase activity -> no proline hydroxylase -> SCURVY BEEESSHH
Multiple myeloma is a disorder in which sort of protein modification?
Ubiquitination ( pro-apoptotic factors are being degraded by proteosomes)
What important cancer fighting genes depend on acytylation modification, in order for transcriptional function to occur?
Tumor suppressing genes
What are 2 diseases associated with histone acetylation (HAT’s and HDAC’s)
- Rubinstein-Taybi Syndrome
2. Leukemia
What is leukemia a result of?
- Chromosomal translocations leading to gain of function fusion proteins
- Fusion of transcriptional regulators with HATs or HDACs, altering the activity of the regulators
What type of malignancy is leukemia?
A hematopoietic malignancy
What mutation does Rubinstein-Taybi Syndrome result from?
Results from mutations in one copy of the CREB binding protein (CBP) gene.
What type of disorder is Rubinstein-Taybi Syndrome?
It is a rare genetic multisystem disorder (affects 1/125,000).
Name 3 disease that arise from mutations in DNA control elements
Thalassemias: (beta, and gamma-delta-beta)
Hemophilia B Leyden
Fragile X-Syndrome
What is Beta Thalassemia a result of?
Deficient production of beta-globin protein.
Due to mutation in the beta-globin promoter- reducing the amount of beta-globin mRNA, thus less proteins are produced
(less promotion = less transcription)
What form of anemia is Beta Thalassemia?
An inherited mild form of anemia
What is Gamma-delta-beta Thalassemia a result of?
Due to deletion of the locus control region (LCR) of the beta-globin gene cluster, resulting in the loss of globin transcription.
What form of anemia is Gamma-delta-beta Thalassemia?
Usually more severe form of anemia than beta.
What is hemophilia B leyden a result of?
inherited mutations in a DNA control element in the promoter of the Factor IX gene.
What type of disease is hemophilia B leyden and what are its effects?
X-linked disease that affects clotting. Tends to get partially better at puberty.(usually males)
What is Fragile X-Syndrome a result of?
High number of CGG repeat in the 5’ region of the FMR1 gene (>200 in mutant vs ~6-50 in normal).
This facilitates methylation of the cytosine residues in CpG islands and transcriptional inactivation of the FMR1 gene.
Describe 3 particular human disorders that arises from a mutation in a sequence specific DNA binding protein
- Craniosynostosis
- Androgen insensitivity syndrome (AIS)
- Waardenburg Syndrome type II
What is Craniosynostosis a result of?
a result of a mutation in the homeodomain protein MSX2.
What is the homeodomain protein MSX2 required for?
MSX2 is normally required for proper craniofacial development by affecting the transcription of a number of genes important in this process.
What is Craniosynostosis characterized by?
Characterized by the premature closure of one or more sutures in the skull.
What is Androgen insensitivity syndrome (AIS) a result of?
Mutations in either the DNA binding domain or the ligand binding domain of the androgen receptor (a zinc finger DNA binding protein).
What gender does Androgen insensitivity syndrome (AIS) affect?
It occurs in males who are a normal karyotype (46 X,Y),
What are some characteristics of AIS
AIS includes feminization or undermasculinization of the external genitalia at birth, abnormal secondary sexual development in puberty, and infertility.
What is Waardenburg Syndrome type II a result of?
Mutations in the microphthalmia-associated transcription factor (MITF) gene.
What does the microphthalmia-associated transcription factor (MITF) gene encode for?
MITF: a transcription factor (bHLH Sequence Specific DNA binding protein) that plays a major role in the development of melanocytes
Symptoms of Waardenburg Syndrome type II?
characterized by deafness, pigmentation anomalies of the eyes, and other pigmentation defects (hair, skin).
CREB binding protein (CBP) gene is essential for what?
CBP is a HAT and so it serves as a transcriptional coactivator for many different transcription factors responsible for regulating cell growth
Mutation in the homeodomain protein MSX2 results in what disorder?
Craniosynostosis
Alzheimer’s Disease (AD) is a result of the build up of which 2 important proteins?
Amyloid beta 42 (AB42), Tau proteins
What proteins coded for on ch.21 can lead to AD?
Beta-amyloid precursor proteins
What 2 enzymes results in the production of Amyloid Beta 42 protein?
Beta secretase followed by gamma-secretase
Are Tau proteins hyper/hypo phosphorylated?
What structures do they result in?
Are they Intra/extracellular?
They are hyperphosphorylated
- Result in neurofibrillary tangles.
- Intracellular
Apo E4 results in increase or decrease in beta amyloid plaques?
Increase
Apo E4 polymorphism is found on what ch?
ch. 19
Presinilin (PSEN) 2 Mutant is found on what ch?
ch. 1
Presinilin (PSEN) 1 mutant results in what phenotype?
Increase production of amyloid beta 42 (AB42)
The presence of what protein results in Prion’s disease?
PrP^SC
Prion disease in cows are termed what?
Bovine Spongiform Encephalopathy (BSE)
What happens when humans consume cows infected with Bovine Spongiform Encephalopathy (BSE)?
Humans get new resulting disease:
Variant Creutzfeld-Jakob Disease (vCJD)
What type of prion disease mode of transmission results in 90% of all acquisition?
Sporadic acquisition
A mutation in what gene, on what chromosome results in Genetic acquisition Prion’s Disease?
PRNP gene, ch 20
What is are the secondary structures associated with normal PrPc and Infection PrPsc proteins?
PrPc = alpha helical PrPsc = beta sheet
Name two neurodegenerative diseases discussed in class that are associated with beta-amyloid plaques
Alzheimers, Prion Disease
Name four proteins that can accumulate in the brain and be involved in neurodegenerative disorders?
Synuclein, Beta amyloid, Tau, TDP43 (ALS)
Parkinson’s Disease is due to the presence of what protein being misfolded?
alpha-synuclein
What are the symptoms of Rubinstein-Taybi Syndrome?
Growth retardation,
mental retardation,
craniofacial dysmorphism, abnormally broad thumbs and great toes.
Tumor suppressing genes depend on what type of protein modification for transcriptional function to occur?
acytylation modification
Spinal muscular atrophy is due to a mutation of what gene?
SMN1 mutation due to splicing defect
Alpha thalassemia results in a mutation in what?
mutation in poly A site (AAUAA)
What model of disease does Reubinstein Taybi syndrome follow?
Haploinsufficiency model (only 1 functional copy of CREB Binding Protein gene)
mutation in the mismatch detection mechanism of which two proteins lead to human nonpolyposis colorectal cancer (hpcc)?
MutS and MutL
Sickle cell anemia base mutation is
E6V
What is dysteratosis congenita a deficiency in?
telomerase deficiency syndrome