Enzyme-linked receptor

An enzyme-linked receptor, also known as a catalytic receptor, is a transmembrane receptor, where the binding of an extracellular ligand causes enzymatic activity on the intracellular side.{{cite book| vauthors = Dudek RW |title=High-yield cell and molecular biology|url=https://books.google.com/books?id=g-d--DOdnQAC&pg=PA19|access-date=16 December 2010|date=1 November 2006|publisher=Lippincott Williams & Wilkins|isbn=978-0-7817-6887-0|pages=19–}} Hence a catalytic receptor is an integral membrane protein possessing both catalytic, and receptor functions.{{cite journal |vauthors=Alexander SP, Mathie A, Peters JA | title = Catalytic Receptors | journal = Br. J. Pharmacol. | volume = 150 Suppl 1 | issue = S1| pages = S122–7 |date=February 2007 | pmc = 2013840 | doi = 10.1038/sj.bjp.0707205 }}

They have two important domains, an extra-cellular ligand binding domain and an intracellular domain, which has a catalytic function; and a single transmembrane helix. The signaling molecule binds to the receptor on the outside of the cell and causes a conformational change on the catalytic function located on the receptor inside the cell.

Examples of the enzymatic activity include:

Receptor tyrosine kinase, as in fibroblast growth factor receptor. Most enzyme-linked receptors are of this type.{{Cite web |url=http://darwin.nmsu.edu/~molbio/mcb520/lecture10.html |title=lecture10 |access-date=2007-03-03 |archive-url=https://web.archive.org/web/20070525080552/http://darwin.nmsu.edu/~molbio/mcb520/lecture10.html |archive-date=2007-05-25 |url-status=dead }}
Serine/threonine-specific protein kinase, as in bone morphogenetic protein
Guanylate cyclase, as in atrial natriuretic factor receptor

Types

The following is a list of the five major families of catalytic receptors:

class="wikitable"

! Family

! Member

! Gene

! Catalytic activity

! Endogenous ligands

! Synthetic ligands

align="center"

| rowspan="4" align="center" | Erb{{cite journal |vauthors=Alexander SP, Mathie A, Peters JA | title = Catalytic receptors: ErbB family | journal = Br. J. Pharmacol. | volume = 150 Suppl 1 | pages = S146 |date=February 2007 | doi = 10.1038/sj.bjp.0706476 }}

| ErbB1 (epidermal growth factor receptor)

| {{Gene|EGFR}}

| tyrosine kinase {{EC number|2.7.10.1}}

| Epidermal growth factor, amphiregulin, betacellulin, epigen, epiregulin, HB-EGF, TGFa

| GW583340, gefitinib, erlotinib, tyrphostins AG879 and AG1478

align="center"

| ErbB2

| {{Gene|ERBB2}}

| "

align="center"

| ErbB3

| {{Gene|ERBB3}}

| "

| NRG-1, NRG-2

| GW583340, gefitinib, erlotinib, tyrphostins AG879 and AG1478

align="center"

| ErbB4

| {{Gene|ERBB4}}

| "

| Betacellulin, epiregulin, HB-EGF, NRG-1, NRG-2, NRG-3, NRG-4

| GW583340, gefitinib, erlotinib, tyrphostins AG879 and AG1478

align="center"

| rowspan="4" align="center" | GDNF (glial cell-derived neurotrophic factor){{cite journal |vauthors=Alexander SP, Mathie A, Peters JA | title = Catalytic receptors: GDNF family | journal = Br. J. Pharmacol. | volume = 150 Suppl 1 | pages = S147 |date=February 2007 | doi = 10.1038/sj.bjp.0706477 }}

| GFRa1

| {{Gene|GFRa1}}

| "

| GDNF > neurturin > artemin

align="center"

| GFRa2

| {{Gene|GFRa2}}

| "

| Neurturin > GDNF

align="center"

| GFRa3

| {{Gene|GFRa3}}

| "

| Artemin

align="center"

| GFRa4

| {{Gene|GFRa4}}

| "

| Persephin

align="center"

| rowspan="4" align="center" | NPR (natriuretic peptide receptor){{cite journal |vauthors=Alexander SP, Mathie A, Peters JA | title = Catalytic receptors: Natriuretic peptide family | journal = Br. J. Pharmacol. | volume = 150 Suppl 1 | pages = S148 |date=February 2007 | doi = 10.1038/sj.bjp.0706478 }}

| NPR1

| {{Gene|NPR1}}

| guanylyl cyclase {{EC number|4.6.1.2}}

| Atrial natriuretic peptide

align="center"

| NPR2

| {{Gene|NPR2}}

| "

| C-type natriuretic peptide

align="center"

| NPR3

| {{Gene|NPR3}}

| "

| Atrial natriuretic peptide

align="center"

| NPR4

| {{Gene|NPR4}}

| "

| Uroguanylin

align="center"

| rowspan="4" align="center" | trk neurotrophin receptor{{cite journal |vauthors=Alexander SP, Mathie A, Peters JA | title = Catalytic receptors: Neurotrophin family | journal = Br. J. Pharmacol. | volume = 150 Suppl 1 | pages = S149 |date=February 2007 | doi = 10.1038/sj.bjp.0706479 }}

| TrkA

| {{Gene|NTRK1}}

| tyrosine kinase {{EC number|2.7.10.1}}

| Nerve growth factor > NT-3

| GW441756, tyrphostin AG879

align="center"

| TrkB

| {{Gene|NTRK2}}

| "

| Brain-derived neurotrophic factor, NT-4/NT-5 > NT-3

align="center"

| TrkC

| {{Gene|NTRK3}}

| "

| NT-3

align="center"

| p75

| {{Gene|NGFR}}

| "

| NGF, BDNF, NT3, NT4/5

align="center"

| rowspan="10" align="center" | Toll-like{{cite journal |vauthors=Alexander SP, Mathie A, Peters JA | title = Catalytic receptors: Toll-like receptor family | journal = Br. J. Pharmacol. | volume = 150 Suppl 1 | pages = S150 |date=February 2007 | doi = 10.1038/sj.bjp.0706480 }}

| TLR1

| {{Gene|TLR1}}

| "

align="center"

| TLR2

| {{Gene|TLR2}}

| "

| Peptidoglycan

align="center"

| TLR3

| {{Gene|TLR3}}

| "