Kategorier: Alle - receptors - response - domains

af Frandy Castellano Gutierrez 1 år siden

99

Classical Target Drug Receptors

The text discusses various classical drug targets, particularly focusing on G protein-coupled receptors (GPCRs) and their subfamilies. GPCRs, which include the largest group like rhodopsin and secretin/

Classical Target Drug Receptors

Classical Target Drug Receptors

Nuclear

Might contain or have a non-genomic target interacting directly with cytosolic proteins
subfamilies
Class III

small includes receptors for

Vit. D receptor

Thyroid hormones

form obligate heterodimers with RXR

Hybrid class

Class II

include receptors for

xenobiotic

Cyt. P3A for metabolization of drugs

cholesterol

fatty acids

form heterodimers with RXR (retinoid x receptor)

found in nucleus

Class I

primary receptors to steroid hormones

estrogen, progesterone, and androgen

mineralocorticoids

glucocorticoids

form homodimers

found in cytoplasm

response time: hours to days
function
modulates transcription
directly interact with DNA
monomeric
no transmembrane domain
thus separate receptor and DNA binding domains
found in cytoplasm or nucleus of cell
do not reside in membrane

Kinase-Linked

Kinase Receptors
Cytokine Receptors

associated with cytosolic tyrosine kinases (JAK)

no intrinsic kinase activity

Serine/Threonine Kinase

TFG receptor

RTK

TLRs

bacterial infection mediate response

growth factor receptors (EGF and NGF)

End Result: activation or inhibition of nuclear transcription factors by:
suppression or activation of target genes
Ligands
hormones

types

bacterial lipopolysaccharides

insulin

cytokines
growth factors
Function in controlling:

immune response

apoptosis

cell cycle progression

tissue repair

inflammation

response time: hours

1

GPCR

desensitization
Receptor internalization

endocytosis

downregulation of receptor

phosphorylation

Protein Kinase A and C

nonspecific kinases

threorine and serine

GPCR Subfamilies
Subtopic
metabotropic Glu Receptor/Ca Sensor

small groups

GABAb receptors

Secretin/glucagon

intermediate EC tail

peptide hormones

calcitonin

Rhodopsin

short EXC tail on N-terminal

ligands bind to helices of EXC hoops

largest group

purines

neuropeptides

amine neurotransmitters

protanoids and cannabinoids

GPCR ligands
Act on different types of receptors

5-HT

ACh

Opioids
Dopamine
fast response: seconds
composition

7

C-terminal

N-terminal

Ligand-Gated

other biological ligands
respond to intracellular binding signals

atp recepots

calcium binding receptors

arachadonic acid sensitive receptors
selective channels
Cation selective pores

anion selective pores

Receptors

GABA

mediate chloride transport

Receptos

5-HT3 receptors

drug target of psychoactive drugs

fast response: milliseconds
Composition
transmembrane domain

4

cytoplasmic domain
extracellular domain
membrane bound