Gene Expression Flashcards Preview

Molecules to Medicine Unit 1 > Gene Expression > Flashcards

Flashcards in Gene Expression Deck (33):
1

The DNA binding domain is located on the ___________ where as the DNA binding element is located on the ____________

Protein; DNA strand

2

__________ is the most important mechanism for determining whether or not genes are expressed.

The first step, the transcription initiation

3

What is the TATA box?

Determines transcription initiation and direct binding of RNA polymerase II

4

Where is the site where general transcription factor's bind?

The TATA box

5

_____________ are generally located 200 base pairs upstream of the transcription site and help regulate in a cell-type specific manner. __________ also help regulate in a cell-type specific manner yet can be very far upstream or down stream from the promoter

Promoter proximal elements; enhancers

6

Beta-Thalassemia is an inherited anemia caused by a mutation on the _____________, reducing the amount of __________

Beta-globin promoter; beta globin mRNA

7

Why does the effects of hemophilic beta Leyden decrease in puberty?

The lack of clotting factor is affected by an inherited mutation in promoter of factor IX. At puberty, the androgen receptor becomes active and can bind to the promoter site through overlap.

8

Fragile X syndrome is caused by an expansion in ___________ in the 5' region, silencing the FMRI gene.

CGG repeats

9

The two classes of activators and repressors are ________ and ____________

Sequence specific DNA binding proteins; Co-factors

10

Sequence specific DNA binding proteins bind to ____________, inserting their alpha helixes in the ___________ of DNA, allows for contact between the amino acid chains and bases of the DNA

Promoter or enhancer elements; Major groove

11

Co-factors bind to ______________

Sequence specific DNA binding proteins

12

The _________ of DNA binding proteins is highly structured, conserved and folded where as the __________ is very unstructured until they bind to co-factors

DNA binding domain; activation domain

13

Describe the structure of the homeodomain proteins (helix-turn-helix)

Has a 60 amino acid domain called a homeodomain; has 3 helices; the second two helices makes the helix-turn-helix motif

14

Describe the structure of the zinc finger protein.

Made of four cystine residues/ or two cystine residues and two histone residues; the fingers recognize and bind to DNA; includes androgen, estrogen and glucocorticoid

15

Describe the structure of the basic leucine receptor protein.

Has a helical structure which allows the protein to dimerize and form zippers; the tail of amino acids interacts with the DNA; involved in the growth and proliferation of cancer

16

Describe the basic helix-loop-helix motif.

This is the basic leucine zipper protein with the loop.

17

Craniosynostosis involved mutation in the __________, MSX2. The mutation has one amino acid mutation which causes the protein to bind more strongly to the DNA, causing hyperactive suture closing.

Homeodomain protein

18

Androgen insensitivity syndrome, which causes feminization of the external genetalia at birth is caused by a mutation in the ______________

Zinc finger binding protein

19

Waardenberg syndrom Type II, which causes deafness and pigment abnormalities is due to a mutation in the _________

Basic helix-loop-helix binding protein

20

Leucine zipper binding proteins can demonstrate combinatorial control by forming __________ or ____________

homodimers; heterdimers

21

The two classes of chromatin remodeling factors include __________ and ____________

DNA dependent ATPases(disrupt histones); HATs and HDACs (reversible)

22

The N-termini of histone are rich in __________ residues.

Lysine

23

What is a HAT?

Histone acetyltransferase; acetylates the n-termini of histones and neutralize the positively charged ends of the lysine rich tail; co-activator

24

What is a HDAC?

Histone deacetylases; removes acetyl groups from the histones and aids in DNA remaining wound; co-repressor

25

In Rubinstein-Taybi syndrome, which involves growth and mental retardation and craniofacial dimorphism, there is a mutation in the _____________ which is a ___________

CREB binding protein; HAT

26

_________ is the more accessible form of chromatin, whereas __________ is always repressed because the DNA is inaccessible

Euchromatin; Heterochromatin

27

The conformation of the DNA-binding protein can be altered by ligand binding such as when __________ transcription factors bind to the steroid hormone.

Zinc finger

28

__________ is normally held in the cytoplasm by binding to an inhibitor, yet when the inhibitor is phosphorylated and degraded, this protein gets the nuclease localization signal and performs activity involved in inflammation

NFkB

29

High intracellular calcium activate calcinurin's phosphotase activity, dephosphorylating _______, allowing it to travel into the nucleus, where is affects transcription of genes involved in immune response in heart function.

NFAT

30

In the absence of Wnt signaling, ___________ is targeted for degradation.

beta-catenin

31

In the presence of Wnt signaling, the Axin-APC-GASK3 is destabilized, preventing_____________

The phosphorylation of beta-catenin

32

p53 is down regulated by binding to the ____________ which masks its activation domain and target it for destruction

MDM2

33

__________ negatively regulate DNA by causing a lack of a basic domain

ID proteins