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Flashcards in section 2 Deck (53)
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1

Whay else target proteins can do

Give the feedback to the receptor

Can be activation or inhibition of this protein, this will lead to a feedback of reaction and will go to the beginning of the cascade ( often to receptor protein ) inhibitiin ghtem or internalizing them

2

What can happen to the signal during transmission

Exponential amplification during transmission

3

Based on the signal receptor, pathways can be divided into 2 main classes

Pathways with cell-surface receptors

Pathways with intracellular receptors

4

Basic strucutre of a cell surface receptor

Extracellular domain with NH2 end, whic have disulfide bond and glycosylation

Hydrophobic transmembrane domain

Cytoplasmic domain with Co2H

5

What AAs make transmembrane domain and how many of them are needed for that

20-25 AAs are needed to cross membrane once 

Hydrophobic AAs (ala, Ile,Leu,Met,Phe,Val,Pro,Gly)

6

Ectodomain (NH2) is often rich in ___ for S-S bonds for folding

Cysteine

7

What secondary structure transmembrane has

Alpha-helix

8

What does it mean that 3 domains of the receptor are interchangeable

you can put an extracellular part of the receptor on the other receptor of the same strucutre and it will work fine

9

If the receptor have only an ectodomain what it can do

It can serve as a buffer system, binding to the hormone in the circulation and increasing its half life

10

What can be the result of cleaved ectodomain in the circulation

The ectodomain cleaved frim the TSH receptor may induce antibodies which binds to the receptor and mimic TSH action ->hyperthyroidism in Grave's disease

11

What will happen to cytoplasmic domain of the receptor upon binding of hormone to the ectodomain

conformational change or indicing the intrinsic enzymatic acitvity or recruitng someone

12

Many signaling proteins are activated by phosphorylation at the AAs:

Serine, threonine and tyrosine on OH group

13

Who is the phosphate donor in phosphorylation

ATP

14

Phosphorylation causes

Conformational change of the protein

15

What signaling proteins that are activated by phosphorylation will perform signal amplification

Kinases

16

Phosphorylation can be reversed by

Phosphatases

17

What AAs are phosphorylated usually

Serine and threonine 

18

When tyrosine is usually phosphorylated and what is their role

In the beginning of the cascade

They serve as a docking sites for down signalling rather than further phosphorylation

19

What is the name for tyrosine domains that will be phosphorylated

SH2 and SH3 domains

20

3 major types of cell surface receptors

21

What happens to GPCR upon binding of the signal 

G alpha is released and then it goes to adenylyl cyclase or other enzyme to activate it

22

5 types of Galpha subunits

23

What type of receptors is the most numerous class

G-protein couples receptors

24

How many trans membrane alpha-helices has GPCR

7

25

Examples of endocrine and non-endocrine signals acting through GPCR

Many receptors of non-endocrine signals also act via
G-proteins. Examples: glutamate (neurotransmitter),
thrombin, odorants and photoreceptors
-Examples of endocrine hormone receptors are TRH,
GnRH, TSH, LH, FSH, ACTH, GHRH and oxytocin

26

Does one hormone is specific to one G-protein?

No, it can use more and also G protein use may change during development and also concentration of hormone

27

2 types of tyrosine kinase coupled receptors

Receptors with an intergrated (intrinsic) kinase activity 

Receptors that recruit a kinase

28

insulin receptor is in what class of receptors

Intrinsic tyrosine kinase activity

29

How many parts insulin receptor has

Hetero-tetrameric (2 alpha and 2 beta held together by S-S bonds)

30

What domain alpha or beta has a transmembrane

β subunit about 618 a.a.: Ectodomain
193 a.a., transmembrane domain 23
a.a., cytoplasmic domain 402 a.a.