Secretin family receptor proteins, also known as Family B or family 2 of

G-protein coupled receptors G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related p ...

are regulated by

peptide hormones Peptide hormones or protein hormones are hormones whose molecules are peptide, or proteins, respectively. The latter have longer amino acid chain lengths than the former. These hormones have an effect on the endocrine system of animals, including ...

from the

glucagon hormone family Glucagon/gastric inhibitory polypeptide/secretin/vasoactive intestinal peptide hormones are a family of evolutionarily related peptide hormones that regulate activity of G-protein-coupled receptors from the secretin receptor family. A number of ...

. The family is different from

adhesion G protein-coupled receptors Adhesion G protein-coupled receptors (adhesion GPCRs) are a class of 33 human protein receptors with a broad distribution in embryonic and larval cells, cells of the reproductive tract, neurons, leukocytes, and a variety of tumours. Adhesion GP ...

. The secretin-receptor family of GPCRs include

vasoactive intestinal peptide receptor There are two known receptors for the vasoactive intestinal peptide (VIP) termed VPAC1 and VPAC2. These receptors bind both VIP and pituitary adenylate cyclase-activating polypeptide (PACAP) to some degree. Both receptors are members of the 7 ...

s and receptors for

secretin Secretin is a hormone that regulates water homeostasis throughout the body and influences the environment of the duodenum by regulating secretions in the stomach, pancreas, and liver. It is a peptide hormone produced in the S cells of the duoden ...

calcitonin Calcitonin is a 32 amino acid peptide hormone secreted by parafollicular cells (also known as C cells) of the thyroid (or endostyle) in humans and other chordates. in the ultimopharyngeal body. It acts to reduce blood calcium (Ca2+), opposing ...

and

parathyroid hormone Parathyroid hormone (PTH), also called parathormone or parathyrin, is a peptide hormone secreted by the parathyroid glands that regulates the serum calcium concentration through its effects on bone, kidney, and intestine. PTH influences bone r ...

/parathyroid hormone-related peptides. These receptors activate

adenylyl cyclase Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction: :A ...

and the phosphatidyl-inositol-calcium pathway. The receptors in this family have 7

transmembrane A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...

helices A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helice ...

,; ; like rhodopsin-like GPCRs. However, there is no significant sequence identity between these two GPCR families and the secretin-receptor family has its own characteristic

7TM G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related p ...

signature. The secretin-receptor family GPCRs exist in many animal species. Data mining with the

Pfam Pfam is a database of protein families that includes their annotations and multiple sequence alignments generated using hidden Markov models. The most recent version, Pfam 35.0, was released in November 2021 and contains 19,632 families. Use ...

signature has identified members in fungi, although due to their presumed non-hormonal function they are more commonly referred to as

Adhesion G protein-coupled receptor Adhesion G protein-coupled receptors (adhesion GPCRs) are a class of 33 human protein receptors with a broad distribution in embryonic and larval cells, cells of the reproductive tract, neurons, leukocytes, and a variety of tumours. Adhesion GP ...

s, making the ''Adhesion'' subfamily the more basal group. Three distinct sub-families (B1-B3) are recognized.

Subfamily B1

Subfamily B1 contains classical

hormone receptor A hormone receptor is a receptor molecule that binds to a specific chemical messenger . Hormone receptors are a wide family of proteins made up of receptors for thyroid and steroid hormones, retinoids and Vitamin D, and a variety of other receptor ...

s, such as receptors for

and

glucagon Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It raises concentration of glucose and fatty acids in the bloodstream, and is considered to be the main catabolic hormone of the body. It is also used as a medication to trea ...

, that are all involved in cAMP-mediated signalling pathways. * Pituitary adenylate cyclase-activating polypeptide type 1 receptor ** PACAPR (ADCYAP1R1) * Calcitonin receptor ** CALCR *

Corticotropin-releasing hormone receptor Corticotropin-releasing hormone receptors (CRHRs), also known as corticotropin-releasing factor receptors (CRFRs) are a G protein-coupled receptor family that binds corticotropin-releasing hormone (CRH). There are two receptors in the family, ...

CRHR1 Corticotropin-releasing hormone receptor 1 (CRHR1) is a protein, also known as CRF1, with the latter (CRF1) now being the IUPHAR-recommended name. In humans, CRF1 is encoded by the ''CRHR1'' gene at region 17q21.31, beside micrototubule-associat ...

; CRHR2 * Glucose-dependent insulinotropic polypeptide receptor/Gastric inhibitory polypeptide receptor **

GIPR The gastric inhibitory polypeptide receptor (GIP-R), also known as the glucose-dependent insulinotropic polypeptide receptor, is a protein that in humans is encoded by the ''GIPR'' gene. GIP-R is a member of the 7-transmembrane protein family, a ...

Glucagon receptor The glucagon receptor is a 62 kDa protein that is activated by glucagon and is a member of the class B G-protein coupled family of receptors, coupled to G alpha i, Gs and to a lesser extent G alpha q. Stimulation of the receptor results in the ...

GCGR The glucagon receptor is a 62 kDa protein that is activated by glucagon and is a member of the class B G-protein coupled family of receptors, coupled to G alpha i, Gs and to a lesser extent G alpha q. Stimulation of the receptor results in the a ...

* Glucagon receptor-related **

GLP1R The glucagon-like peptide-1 receptor (GLP1R) is a receptor protein found on beta cells of the pancreas and on neurons of the brain. It is involved in the control of blood sugar level by enhancing insulin secretion. In humans it is synthesised by t ...

;

GLP2R Glucagon-like peptide-2 receptor (GLP-2R) is a protein that in human is encoded by the ''GLP2R'' gene located on chromosome 17. Function The GLP2 receptor (GLP2R) is a G protein-coupled receptor superfamily member closely related to the glucago ...

; * Growth hormone releasing hormone receptor **

GHRHR The growth-hormone-releasing hormone receptor (GHRHR) is a G-protein-coupled receptor that binds growth hormone-releasing hormone. The GHRHR activates a Gs protein that causes a cascade of cAMP via adenylate cyclase. Function This gene, exp ...

* Parathyroid hormone receptor **

PTHR1 Parathyroid hormone/parathyroid hormone-related peptide receptor, also known as parathyroid hormone 1 receptor (PTH1R), is a protein that in humans is encoded by the ''PTH1R'' gene. PTH1R functions as a receptor for parathyroid hormone ( PTH) an ...

;

PTHR2 Parathyroid hormone 2 receptor is a protein that in humans is encoded by the ''PTH2R'' gene. Function The protein encoded by this gene is a member of the G protein-coupled receptor family 2. This protein is a receptor for parathyroid hormone (P ...

* Secretin receptor ** SCTR *

Vasoactive intestinal peptide receptor There are two known receptors for the vasoactive intestinal peptide (VIP) termed VPAC1 and VPAC2. These receptors bind both VIP and pituitary adenylate cyclase-activating polypeptide (PACAP) to some degree. Both receptors are members of the 7 ...

VIPR1 Vasoactive intestinal polypeptide receptor 1 also known as VPAC1, is a protein, that in humans is encoded by the ''VIPR1'' gene. VPAC1 is expressed in the brain ( cerebral cortex, hippocampus, amygdala), lung, prostate, peripheral blood leuk ...

;

VIPR2 Vasoactive intestinal peptide receptor 2 also known as VPAC2, is a G-protein coupled receptor that in humans is encoded by the ''VIPR2'' gene. Tissue distribution VIPR2 is expressed in the uterus, prostate, smooth muscle of the gastroint ...

Subfamily B2

Subfamily B2 contains receptors with long extracellular N-termini, such as the leukocyte cell-surface antigen

CD97 Cluster of differentiation 97 is a protein also known as BL-Ac 2'' encoded by the ''ADGRE5'' gene. CD97 is a member of the adhesion G protein-coupled receptor (GPCR) family. Adhesion GPCRs are characterized by an extended extracellular region ofte ...

; calcium-independent receptors for

latrotoxin A latrotoxin is a high-molecular mass neurotoxin found in the venom of spiders of the genus ''Latrodectus'' (widow spiders) as well as at least one species of another genus in the same family, ''Steatoda nobilis''. Latrotoxins are the main active ...

and

brain-specific angiogenesis inhibitor Brain-specific angiogenesis inhibitors are G-protein coupled receptors belonging to the class B secretin subfamily. Members include: * Brain-specific angiogenesis inhibitor 1 * Brain-specific angiogenesis inhibitor 2 * Brain-specific angioge ...

receptors amongst others. They are otherwise known as

s. *

Brain-specific angiogenesis inhibitor Brain-specific angiogenesis inhibitors are G-protein coupled receptors belonging to the class B secretin subfamily. Members include: * Brain-specific angiogenesis inhibitor 1 * Brain-specific angiogenesis inhibitor 2 * Brain-specific angioge ...

BAI1 Brain-specific angiogenesis inhibitor 1 is a protein that in humans is encoded by the ''BAI1'' gene. It is a member of the adhesion-GPCR family of receptors. Function Angiogenesis is controlled by a local balance between stimulators and inhib ...

;

BAI2 BAI or Bai may refer to: BAI Organizations *BAI Communications, telecommunications infrastructure company * BAI (organization), professional organization for financial services in the United States *Badminton Association of India, India's gov ...

;

BAI3 Brain-specific angiogenesis inhibitor 3 is a protein that in humans is encoded by the ''BAI3'' gene. BAI1, a p53-target gene, encodes brain-specific angiogenesis inhibitor, a seven-span transmembrane protein and is thought to be a member of the ...

* CD97 antigen **

* EMR hormone receptor **

CELSR1 Cadherin EGF LAG seven-pass G-type receptor 1 also known as flamingo homolog 2 or cadherin family member 9 is a protein that in humans is encoded by the ''CELSR1'' gene. Function The protein encoded by this gene is a member of the flamingo su ...

;

CELSR2 Cadherin EGF LAG seven-pass G-type receptor 2 is a protein that in humans is encoded by the ''CELSR2'' gene. The protein encoded by this gene is a member of the flamingo subfamily, part of the cadherin superfamily. The flamingo subfamily consists ...

;

CELSR3 Cadherin EGF LAG seven-pass G-type receptor 3 is a protein that in humans is encoded by the ''CELSR3'' gene. The protein encoded by this gene is a member of the flamingo subfamily, part of the cadherin superfamily. The flamingo subfamily consist ...

;

EMR1 EGF-like module-containing mucin-like hormone receptor-like 1 also known as F4/80 is a protein encoded by the ''ADGRE1'' gene. EMR1 is a member of the adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region o ...

;

EMR2 EGF-like module-containing mucin-like hormone receptor-like 2 also known as CD312 (cluster of differentiation 312) is a protein encoded by the ''ADGRE2'' gene. EMR2 is a member of the adhesion-GPCRs, adhesion GPCR family. Adhesion GPCRs are chara ...

;

EMR3 EGF-like module-containing mucin-like hormone receptor-like 3 is a protein encoded by the ''ADGRE3'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meani ...

;

EMR4 The EGF module-containing Mucin-like hormone Receptors (EMRs) are closely related subgroup of G protein-coupled receptors (GPCRs). These receptors have a unique hybrid structure in which an extracellular epidermal growth factor (EGF)-like doma ...

* GPR56 orphan receptor **

GPR56 G protein-coupled receptor 56 also known as TM7XN1 is a protein encoded by the ''ADGRG1'' gene. GPR56 is a member of the adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protei ...

;

GPR64 G protein-coupled receptor 64 also known as HE6 is a protein encoded by the ''ADGRG2'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generatio ...

;

GPR97 G-protein coupled receptor 97 also known as adhesion G protein-coupled receptor G3 (ADGRG3) is a protein that in humans is encoded by the ''ADGRG3'' gene. GPR97 is a member of the adhesion-GPCRs, adhesion GPCR family. Adhesion GPCRs are characteriz ...

;

GPR110 Probable G-protein coupled receptor 110 is a protein that in humans is encoded by the ''GPR110'' gene. This gene encodes a member of the adhesion-GPCR receptor family. Family members are characterized by an extended extracellular region with a var ...

;

GPR111 Probable G-protein coupled receptor 111 is a protein that in humans is encoded by the ''GPR111'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ' ...

;

GPR112 G protein-coupled receptor 112 is a protein encoded by the ''ADGRG4'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' ...

;

GPR113 GPR113 is a gene that encodes the Probable G-protein coupled receptor 113 protein. Gene The ''Homo sapiens'' GPR113 gene is located on chromosome 2 (2p23.3). This gene spans the length of a 38.65kb region from base 26531041 to 26569685 on the neg ...

;

GPR114 G protein-coupled receptor 114 is a protein encoded by the ''ADGRG5'' gene. GPR114 is a member of the adhesion-GPCRs, adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protein mo ...

;

GPR115 Probable G-protein coupled receptor 115 is a protein that in humans is encoded by the ''GPR115'' gene. References Further reading * * * * * * G protein-coupled receptors {{transmembranereceptor-stub ...

;

GPR123 Probable G-protein coupled receptor 123 is a protein that in humans is encoded by the ''GPR123'' gene. It is a member of the adhesion-GPCR family of receptors. Family members are normally characterized by an extended extracellular region with a v ...

;

GPR125 Adhesion G-protein coupled receptor A3 (ADGRA3), also known as GPR125, is an adhesion GPCR that in humans is encoded by the ''Adgra3'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the M ...

;

GPR126 G protein-coupled receptor 126 also known as VIGR and DREG is a protein encoded by the ''ADGRG6'' gene. GPR126 is a member of the adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region often possessing N-termina ...

; GPR128;

GPR133 Probable G-protein coupled receptor 133 is a protein that in humans is encoded by the ''GPR133'' gene. This gene encodes a member of the adhesion-GPCR family of receptors. Family members are characterized by an extended extracellular region with ...

;

GPR144 Probable G-protein coupled receptor 144 is a protein that in humans is encoded by the ''GPR144'' gene. This gene encodes a member of the adhesion-GPCR family of receptors. Family members are characterised by an extended extracellular region wit ...

;

GPR157 Probable G-protein coupled receptor 157 is a protein that in humans is encoded by the ''GPR157'' gene. References Further reading * * * * * G protein-coupled receptors {{transmembranereceptor-stub ...

Latrophilin receptor Latrophilins are a group of highly conserved G-protein coupled receptors from the adhesion G protein-coupled receptor family. These receptors were originally identified based on their ability to bind to a component of black widow spider venom ...

ELTD1 EGF, latrophilin and seven transmembrane domain-containing protein 1 is a latrophilin-like orphan receptor of the adhesion G protein-coupled receptor family. In humans this protein is encoded by the ''ELTD1'' gene. ELTD1 appears to have a role i ...

;

LPHN1 Latrophilin 1 is a protein that in humans is encoded by the ''ADGRL1'' gene. It is a member of the adhesion-GPCR family of receptors. Family members are characterized by an extended extracellular region with a variable number of protein domains ...

;

LPHN2 Latrophilin 2 is a protein that in humans is encoded by the ''ADGRL2'' gene. This gene encodes a member of the latrophilin subfamily of G-protein coupled receptors (GPCR). Latrophilins may function in both cell adhesion and signal transduction. In ...

;

LPHN3 Latrophilin 3 is a protein that in humans is encoded by the ''ADGRL3'' gene. Function This gene encodes a member of the latrophilin subfamily of G protein-coupled receptors (GPCR). Latrophilins may function in both cell adhesion and signal tra ...

* Ig-hepta receptor **

GPR116 Probable G-protein coupled receptor 116 is a protein that in humans is encoded by the ''GPR116'' gene. GPR116 has now been shown to play an essential role in the regulation of lung surfactant homeostasis. References Further reading * ...

Subfamily B3

Subfamily B3 includes

Methuselah Methuselah () ( he, מְתוּשֶׁלַח ''Məṯūšélaḥ'', in pausa ''Məṯūšālaḥ'', "His death shall send" or "Man of the javelin" or "Death of Sword"; gr, Μαθουσάλας ''Mathousalas'') was a biblical patriarch and ...

and other

Drosophila ''Drosophila'' () is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or (less frequently) pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many s ...

proteins. Other than the typical seven-transmembrane region, characteristic structural features include an amino-terminal extracellular domain involved in ligand binding, and an intracellular loop (IC3) required for specific G-protein coupling. *

Diuretic hormone receptor A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics i ...

Unclassified members

HCTR-5; HCTR-6; KPG 006; KPG 008

References

{{G protein-coupled receptors Protein domains Protein families G protein-coupled receptors