FMS Week 1 Flashcards Preview

FMS > FMS Week 1 > Flashcards

Flashcards in FMS Week 1 Deck (198):
1

Ataxia telangiectasia

Results from mutations in ATM gene, spider veins, loss of motor control, immunodeficiency, sensitivity to radiation

2

Neurofibromatosis

Inherited cancer syndrome caused by mutation in NF1 gene

3

DNA polymerase δ

Leading and lagging strand synthesis and base excision repair

4

XPC

NER gene, xeroderma pigmentosum assoc.

5

GEF

A GTP meditator for G-proteins

6

What is the second step of RNA modification?

The RNA is cleaved at the polyA signal, the tail is synthesized by polyA polymerase, PABPN1 (poly A binding protein 1) stops synthesis at 200-300bp

7

what are the similarities of the 2 apoptosis pathways?

they both activate the same effector caspases

8

mutation in mismatch repair gene (MMR)

Lynch syndrome, most commonly results in hereditary non-polyposis colon cancer (HNPCC)

9

2 types of anchoring junctions

adherens junctions and desmosomes

10

aflatoxins

carcinogens from peanut/grain mold

11

what is the biggest difference between dephosphorylation and GTP hydrolysis?

GTP hydrolysis is not mediated by an enzyme

12

Bloom syndrome

results from mutation in BLM gene of homologous recombination, short stature, narrow face with prominent nose, skin-sun sensitivity, facial rash, immunodeficiency, cancer, possible mental retardation

13

translation initiation

40s subunit joins mRNA at 5' region, scans for the first start codon in the proper context, 60s subunit joins and translation begins

14

carcinogens from charred meat

heterocyclic amines

15

aneuploidy

less or more than an exact multiple of the haploid set of chromosomes

16

erythromycin

binds to the 50s subunit and inhibits translocation (prokaryotes)

17

what type of molecules are second messengers?

small molecules that aplify the signal of the first messenger (ligand)

18

1000-fold increase of skin cancers, "children of the night"

Xeroderma pigmentosum

19

where does DNA methylation occur?

C-G adjacent basepairs

20

JAK-STAT Pathway

cytokines bind receptor, JAKs phosphorylate each other, JAK binds and activates STAT through phosphorylation, STAT (complex) is a transcription factor

21

cycloheximide

inhibits translocation (blocks translational elongation)(eukaryotes)

22

What is PTEN?

PTEN inhibits PIP2 to PIP3 secondary messaging, indirectly leading to promotion of apoptosis (AKT indirectly leads to degradation of p53) and inhibition of cell growth

23

Werner Syndrome

results from mutations in WRN gene of homologous recombination and DNA replication, short stature, premature aging, cancer

24

CNV

copy number variants

25

CDKN2 family

bind and inhibit only D-CDK4/6 (restriction point)

26

What effect do Xrays have on DNA?

strand breakage

27

tight junction

seals gaps between epithelial cells

28

what is myc?

a transcription factor for cyclin D

29

receptor of RAS-MAPK

tyrosine kinase

30

ATM gene

gene associated with homologous recombination in double-stranded breakage

31

how do hydrophillic signals act?

surface receptors trigger signal transduction through to effector proteins that can act both inside and outside the nucleus

32

what facilitates phosphorylation?

ATP (to ADP) and a protein kinase

33

XPA

NER gene, xeroderma pigmentosum assoc.

34

DNA mismatch repair

Guided by mismatch proofreading proteins cut out segment of strand with "nick" so that DNA pol can resynthesize

35

prophase

chromosomes condense, mitotic spindle forms, nucleus disassembles, chromosomes begin attaching to mitotic spindle

36

metaphase

chromosomes line up

37

cytokine

small proteins that stimulate differentiation/proliferation of immune cells

38

Bad

apoptotic sensor

39

FANC

interstrand DNA crosslink repair gene, assoc. w/ fanconi anemia

40

pemphigus vulgaris

blistering disease caused by autoantibodies to desmosomal proteins

41

DNA polymerase ε

Leading strand synthesis and base excision repair

42

7-TM receptor

large serpentine domain that is usually coupled to large G-protein

43

membrane-mediated signalling

signals communicate through the membranes of adjacent cells

44

what family is p16?

CDKN2

45

2 ways splicing can regulate translation

alternative introns/exons, differential splice sites within an intron

46

cyclin-CDK G2/M transition (entry to mitosis)

A-CDK1

47

what is the biggest difference between dephosphorylation and GTP hydrolysis?

GTP hydrolysis is not mediated by an enzyme

48

carcinogens from peanut/grain mold

aflatoxins

49

Ras

small G-protein, activated (GTP) through tyrosine-kinase complexes

50

what are the 2 pathways of apoptosis?

Intrinsic (mitochondrial) and extrinsic (death receptor)

51

what is a procaspase?

an inactive caspases that cleave eachother to activate, then cleave executioner caspases to activate them in a cascade

52

snRNPs

guide splicing process, make up the splicosome

53

Xeroderma Pigmentosum

high risk of all skin cancers, results from mutation in any XP gene (NER gene): XPA, XPC, ERCC2, ERCC4, ERCC5

54

actin-linked cell matrix junction

actin anchors to extracellular matrix (basal lamina). basal "adherens"

55

What are the pro-apoptotic sensors and what do they do?

Bad, Bim, Bid, Puma, and Noxa. They are BH-3 only proteins. They sense cellular stress/damage and take out the anti-apoptotic regulators to start apoptosis.

56

receptor of PI3K-AKT pathway?

receptor dimers with intrinsic kinase domains or that bind intracellular kinases

57

direct ligation

DNA-protein kinase and Ku allign dsDNA breaks, usually results in bp deletions

58

Restriction point pathway

Growth factors trigger signalling pathway that upregulates myc (cyclin D transcription factor), cycD activates CDK4/6, D-CDK4/6 phosphorylates Rb, inactivated Rb (hyperphosphorylated) no longer inactivates E2F, freed and activated E2F is transcription factor for S phase genes such as cyclin A

59

WRN

gene involved in homologous recombination and DNA replication, codes for a DNA helicase

60

Bcl-XL

anti-apoptotic regulator

61

BRCA1/2

gene associated with homologous recombination in double-stranded breakage

62

non-homologous end joining

resects ends to uncover 2-3 nucleotide micro-homology

63

fragile-X syndrome

caused by nucleotide expansion mutations

64

RAS-MAPK pathway

growth factors bind receptor, Ras is activated by GTP exchange factor (GEF), Ras activates (p) Raf, Raf activates (p) Mek, Mek activates (p) Erk (MAPK). Erk phosphorylates target proteins including transcription factors such as Myc

65

membrane-mediated signalling

signals communicate through the membranes of adjacent cells

66

ERCC2

NER gene, xeroderma pigmentosum assoc.

67

GPCRs

large G-proteins

68

how to hydrophobic signals act?

the enter the plasma membrane and bind with receptors in the cytoplasm, then move into the nucleus

69

myotonic dystrophy

caused by nucleotide expansion mutations

70

euchromatin

more relaxed chromatin, more transcriptionally active

71

what is p53?

a tumor supressor gene that is involved in the restriction point pathway, DNA damage checkpoint pathway, and the apoptosis pathway

72

cAMP-PKA pathway

Peptide hormone is ligand for 7TM receptor, which activates adenylate cyclase, which activates (p) cAMP, which removes inhibitor on protein kinase A (PKA), PKA enters the nucleus and activates transcription factors

73

receptor of JAK-STAT

cytokine receptor coupled to JAK

74

steroid receptors

gene-specific transcription factors that are activated by hormone binding

75

how does methylation deactivate genes?

attracts histone deacytylases (HDAC), compacts histones around promoters

76

mitotic/spindle assembly checkpoint

Mad2 recruited to kinetochore, Mad2 inhibits APC/C (an ubiquitin ligase), mitotic proteins and cyclins (A&B) cannot be degraded by 26S, and the cell cycle is arrested in mitosis until securin can restore loose chromatids

77

steroid receptors

gene-specific transcription factors that are activated by hormone binding

78

cytokine

small proteins that stimulate differentiation/proliferation of immune cells

79

HNPCC

"Lynch syndrome", colorectal cancer, MMR mutation: MSH2/3/6, MLH1, PMS1/2

80

NF1

a gene that accumulates regulates Ras when growth factor is not present to initiate it

81

desmosomes

connects intermediate filaments between cells

82

what activates apoptosis?

caspases (cysteine proteases that cleave proteins after aspartic residues)

83

CDKN1 family

CKI family that inhibits multiple cyclin-CDK complexes, broad spectrum

84

streptomycin (aminoglycosides)

inhibit initation and cause misreading of mRNA (prokaryotes)

85

Beta-thalassemias

mutation in Beta-globin subunit of hemoglobin caused by mutation in promoter, often the result of splice-site mutations

86

what facilitates dephosphorylation?

protein phosphatase

87

chemokine

agent that attracts motile cells through receptor mediated signalling

88

first messenger of cAMP-PKA pathway

peptide hormones (epinephrine etc.)

89

Proofreading

3' to 5' exonuclease activity of DNA pol

90

Neurofibromatosis

Inherited cancer syndrome caused by mutation in NF1 gene

91

Telomerase

synthesizes incomplete 5' ends of the lagging strands, levels are mostly high in rapidly dividing cells (embryos and cancer)

92

CKIs

cyclin-dependent kinase inhibitors, sterically inhibit

93

IP3-PKC pathway

Receptor activates large G protein, which activates phospholipase C, which cleaves PI4,5P2 to IP3 and DAG. IP3 binds to SER Ca channels to release Ca. Ca binds to PKC which has bound to DAG, activating the complex, PKC complex phosphorylates many substrates including nuclear transcription and cytoplasmic regulatory proteins

94

Describe a SINE

Short interspersed nuclear elements, non-coding DNA, use rev transcriptase from LINES, most common are ALU repeats

95

RISC

RNA-induced silencing complex, pairs miRNAs with compliments on mRNA for possible translational repression and rapid/eventual degredation

96

PI3K-AKT pathway

ligand binds receptor, facilitates phosphorylation of PIP2 to PIP3, PIP3 stimulates PDK1, which activates AKT(PKB) through phosphorylation, AKT(PKB) is a master regulator for cell growth and against programmed cell death

97

what is p53s role in the restriction point?

p53 is a growth inhibitor that upregulates p16 and inhibits the restriction point pathway, leaving Rb in a hypophosphorylated state (bonded to E2F)

98

iPSC

induced pluripotent stem cells

99

MCL1

anti-apoptotic regulator

100

differences between apoptosis and necrosis

necrosis is pathological rather than physiological, membranes break up, contents may leak out and cause inflammation.

Apoptosis is physiological [programmed cell death, cell shrinks intact, contents may be released in apoptotic bodies

101

What does the Bcl-2 family do?

They control mitochondrial outer membrane permeability (MOMP)

102

paracrine signalling

signaling molecules that act on nearby cells

103

Which type of nucleotide is more at risk to DNA damage due to metabolism?

purines

104

chemokine

agent that attracts motile cells through receptor mediated signalling

105

heterochromatic

more condensed, repressed chromatin

106

First messenger of RAS-MAPK

growth factors

107

Large Heterotrimeric G-Protein Function

Ligand stimulates alpha subunit, which can then leave rest of complex to activate an effector molecule, hydrolyzing GTP so the subunit can return to the complex

108

MLH1

MMR gene

109

adherens junctions

connects actin filaments between cells

110

Bim

apoptotic sensor

111

chloramphenicol

inhibits the peptidyl transferase activity of the 50s ribosomal subunit (prokaryotes)

112

PCNA

proliferating cell nuclear antigen, "sliding clamp", inhibited by p21 so that DNA pol cannot stay attached

113

GAP

A GTPase activating protein, indirectly results in GTP hydrolysis

114

how does acetylation activate genes?

recruits histone actelation transferase (HAT) to move histones and open gene

115

what facilitates dephosphorylation?

protein phosphatase

116

cyclin-CDK at restriction point

D-CDK4/6

117

Ras

small G-protein, activated (GTP) through tyrosine-kinase complexes, growth factor initiated protein that is often an oncogene when unregulated

118

Base Excision Repair

resects and replaces small lesions (modified bases)

119

translesion DNA replication

NER

120

What are the pro-apoptotic effectors and what do they do?

Bax and Bak. They contain BH domains 1-3. They oligomerize to form pores in the outer mitochondrial membrane making it permeable.

121

puromycin

causes premature chain termination by acting as an analog of aminoacyl-tRNA (prokaryotes and eukaryotes)

122

ERCC5

NER gene, xeroderma pigmentosum assoc.

123

difference between BER and NER

NER is for helix distorting adducts and requires removal of large fragment

124

mitogen

a growth factor that stimulates proliferation

125

spider veins, sensitivity to radiation, loss of motor control

ataxia telangiectasia

126

What is ErbB-2?

A RAS-MAPK type growth factor receptor that can be blocked in certain breast cancers

127

what family is p21?

CDKN1

128

gap junction

"pipeline" allows passage of small water-soluble molecules between cells

129

integrins

allow proteins on outside of cell to sense state of extracellular matrix, connected to actin cytoskeleton

130

Bax

pro-apoptotic effector

131

what is the second messenger in cAMP-PKA pathway?

cAMP

132

cyclin-CDK in S phase (during DNA replication)

A-CDK2

133

Interstrand crosslink repair

repairs big helix distorting lesions, single nucleotide

134

sequence of splicing

Branching nucleotide -OH attacks 5' splice site, then 3'-OH of removed intron attacks 3' splice site leaving exons attached and introns in loop structure

135

Describe a LINE

Long interspersed nuclear elements, non-LTR, non-viral, retrotransposon, Only line-1 can transpose

136

purpose of JAK-STAT Pathway

stimulates blood cell growth and proliferation

137

receptor of IP3-PKC pathway

7TM serpentine

138

first messenger of JAK-STAT

cytokines (blood cell proliferation factors)

139

purpose of PI3K-AKT pathway?

controls cell growth and apoptosis pathways (AKT does through negative control of p53 via MDM2 mediation)

140

mitogen

a growth factor that stimulates proliferation

141

cyclin-CDK G1/S transition (beginning of DNA replication)

E-CDK2

142

PMS2

MMR gene

143

MSH2/6

MMR gene

144

largest class of genes

transcription factors

145

anaphase

separation of sister chromatids

146

what protein controls the restriction point?

Rb (retinoblastoma protein)

147

first messenger of IP3-PKC pathway

selected growth factors, mitogens, immune signals (histamine)

148

DNA polymerase α

DNA replication and primer synthesis

149

DNA damage checkpoint pathway

cyclin-CDKs activate ATM/ATR, ATM/ATR phosporylate and activate Chk1/Chk2, Chks phosphorylate/inhibit substrates like Cdc25 and p53, Cdc25 can no longer dephosphorylate CDKs leaving them inhibited. P53 upregulates p21

150

Which type of nucleotide is more at risk to exogenous DNA damage?

pyrimidines

151

actinomycin D

binds to DNA and blocks RNA Polymerase elongation

152

what facilitates phosphorylation?

ATP (to ADP) and a protein kinase

153

Noxa

apoptotic sensor

154

Bid

apoptotic sensor

155

What are the first steps of RNA modification?

The 7-MeG cap created by enzymes at the CTD (nose) of RNA Pol II and is added just after RNA Pol II leaves the promoter

156

What disease is caused by mutation in the NF1 gene?

Neurofibromatosis

157

DNA methyltransferases

copy methylation patterns in newly replicated DNA in mitosis, "cellular inheritance"

158

what is the execution phase of apoptosis?

executioner or effector caspases degrade cellular components

159

Friedreich ataxia

caused by nucleotide expansion mutations

160

purpose of cAMP-PKA pathway

stimulates transcription of specific genes including regulators of metabolic pathways

161

Nucleotide Excision Repair

Repairs big helix distorting lesions, single nucleotide

162

first messenger of PI3K-AKT pathway?

selected hormones (eg Insulin), growth factors and cell survival ligands

163

Fanconi anemia

results from mutations in FANC genes of interstrand DNA crosslink repair, short stature, developmental abnormalities, bone marrow disorders, cancer

164

Bak

pro-apoptotic effector

165

alpha-Amanitin

toxin from poisonous mushroom Amanita phalloides, inhibitor of RNA pol II

166

What disease is caused by mutation in the NF1 gene?

Neurofibromatosis

167

elements of the core promoter?

TATA box, initiation site (INR), downstream promoting elements (DPE)

168

What is mTOR?

mTOR is activated by AKT. mTOR activates translation by activation the ribosome and inhibiting a translation initiation inhibitor

169

purpose of IP3-PKC pathway

activation of calcium stores and PKC, which plays roles in membrane structure change, transcriptional regulation, immune response, and cell growth

170

what is the apoptotic pathway in most mammalian cells?

intrinsic

171

What are the phases of apoptosis?

initiation phase and execution phase

172

GEF

GTP exchange factor

173

how much of the nuclear genome codes for proteins?

1.5%

174

endocrine signalling

signalling to elsewhere through the circulatory system

175

Puma

apoptotic sensor

176

receptor of cAMP-PKA pathway

7-TM serpentine

177

telophase

mitotic spindle breaks down, two nuclei form, chromosomes decondense, organelles reassemble

178

what disease is caused by autoantibodies to desmosomal proteins?

pemphigus vulgaris

179

tetracycline

binds to the 30s subunit and inhibits binding fo aminoacyl-tRNAs (prokaryotes)

180

Single stranded breaks

PARP (polyADPribose polymerase) senses break and recruits BER enzymes to repair

181

Myc, Max, & Mad

Dimer transcription factors, MycMax acts as activator, MadMax acts as repressor

182

acute myeloid cancers, short stature, developmental abnormalities, bone marrow disorders

fanconi anemia

183

cytokinesis

division of cytoplasm to form 2 new cells (starts in late anaphase and finishes shortly after telophase)

184

ERCC4

NER gene, xeroderma pigmentosum assoc.

185

most important difference about meiosis

crossover during prophase I

186

Bcl-2

anti-apoptotic regulator

187

Homologous recombination

Uses homologous sequence as template to repair double stranded breaks and interstrand crosslinks, "staggered"

188

SNP

single nucleotide polymorphism, across genome, 2 variants across population

189

What are the anti-apoptotic regulators and what do they do?

Bcl-2, Bcl-XL, and MCL1. They contain BH domains 1-4. They keep the outer mitochondrial membrane impermeable.

190

Huntington's disease

caused by nucleotide expansion mutations, autosomal dominant

191

Polycyclic aromatic hydrocarbons

mutagen/carcinogen chemicals from smoke and fossil fuels

192

how much of the genome codes for introns?

26%

193

what is initiation phase of apoptosis?

initiator caspases become active

194

hemidesmosome

anchors intermediate filaments to extracellular matrix (basal lamina). basal "desmosome"

195

cyclin-CDK in mitosis

B-CDK1

196

endocrine signalling

signalling to elsewhere through the circulatory system

197

short stature, premature aging, cancer

Werner Syndrome

198

short stature, narrow face w/ prominent nose, sun-skin sensitivity, butterfly-shaped facial rahs, immunodeficiency, cancer

Bloom syndrome