Summary: 7 transmembrane receptor (Secretin family)
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This is the Wikipedia entry entitled "Secretin receptor family". More...
Secretin receptor family Edit Wikipedia article
| Secretin family of 7 transmembrane receptors | |||||||||
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| Structure of a 31 amino acid fragment of the extracellular N-terminus of the human parathyroid hormone receptor.[1] | |||||||||
| Identifiers | |||||||||
| Symbol | 7tm_2 | ||||||||
| Pfam | PF00002 | ||||||||
| InterPro | IPR000832 | ||||||||
| PROSITE | PDOC00559 | ||||||||
| SCOP | 1bl1 | ||||||||
| SUPERFAMILY | 1bl1 | ||||||||
| OPM superfamily | 6 | ||||||||
| OPM protein | 1fjr | ||||||||
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Secretin family of 7 transmembrane receptors is a family of evolutionarily related proteins.[2]
This family is known as Family B, the secretin-receptor family or family 2 of the G-protein-coupled receptors (GPCR). Many secretin receptors are regulated by peptide hormones from the glucagon hormone family.
The secretin-receptor family GPCRs include vasoactive intestinal peptide receptors and receptors for secretin, calcitonin and parathyroid hormone/parathyroid hormone-related peptides. These receptors activate adenylyl cyclase and the phosphatidyl-inositol-calcium pathway. The receptors in this family have 7 transmembrane helices, 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 signature.
The secretin-receptor family GPCRs exist in many animal species, but have not been found in plants, fungi or prokaryotes. Three distinct sub-families (B1-B3) are recognized.
Contents |
[edit] Subfamily B1
Subfamily B1 contains classical hormone receptors, such as receptors for secretin and glucagon, that are all involved in cAMP-mediated signalling pathways.
- Pituitary adenylate cyclase-activating polypeptide type 1 receptor IPR002285
- Calcitonin receptor IPR003287
- Corticotropin-releasing hormone receptor IPR003051
- Glucose-dependent insulinotropic polypeptide receptor/Gastric inhibitory polypeptide receptor IPR001749
- Glucagon receptor-related IPR003290
- Growth hormone releasing hormone receptor IPR003288
- Parathyroid hormone receptor IPR002170
- Secretin receptor IPR002144
- Vasoactive intestinal peptide receptor IPR001571
[edit] Subfamily B2
Subfamily B2 contains receptors with long extracellular N-termini, such as the leukocyte cell-surface antigen CD97; calcium-independent receptors for latrotoxin (such as O94910, and brain-specific angiogenesis inhibitor receptors (such as O14514) amongst others.
- Brain-specific angiogenesis inhibitor IPR008077
- CD97 antigen IPR003056
- EMR hormone receptor IPR001740
- GPR56 orphan receptor IPR003910
- Latrophilin receptor IPR003924
[edit] Subfamily B3
Subfamily B3 includes Methuselah and other Drosophila 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.
[edit] Unclassified subfamilies
[edit] Unclassified members
HCTR-5; HCTR-6; KPG_006; KPG_008
[edit] References
- ^ PDB 1BL1; Pellegrini M, Bisello A, Rosenblatt M, Chorev M, Mierke DF (September 1998). "Binding domain of human parathyroid hormone receptor: from conformation to function". Biochemistry 37 (37): 12737–43. doi:10.1021/bi981265h. PMID 9737850.
- ^ Harmar AJ (2001). "Family-B G-protein-coupled receptors". Genome Biol. 2 (12): REVIEWS3013. doi:10.1186/gb-2001-2-12-reviews3013. PMC 138994. PMID 11790261. //www.ncbi.nlm.nih.gov/pmc/articles/PMC138994/.
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This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
7 transmembrane receptor (Secretin family) Provide feedback
This family is known as Family B, the secretin-receptor family or family 2 of the G-protein-coupled receptors (GCPRs).They have been described in many animal species, but not in plants, fungi or prokaryotes. Three distinct sub-families are recognised. Subfamily B1 contains classical hormone receptors, such as receptors for secretin and glucagon, that are all involved in cAMP-mediated signalling pathways. Subfamily B2 contains receptors with long extracellular N-termini, such as the leukocyte cell-surface antigen CD97 (P48960); calcium-independent receptors for latrotoxin (such as O94910), and brain-specific angiogenesis inhibitors (such as O14514) amongst others. Subfamily B3 includes Methuselah and other Drosophila proteins (e.g. P83119). 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 [1].
Literature references
-
Harmar AJ; , Genome Biol 2001;2:REVIEWS3013.: Family-B G-protein-coupled receptors. PUBMED:11790261 EPMC:11790261
External database links
| PANDIT: | PF00002 |
| PROSITE: | PDOC00559 |
| Pseudofam: | PF00002 |
| SCOP: | 1bl1 |
| SYSTERS: | 7tm_2 |
This tab holds annotation information from the InterPro database.
InterPro entry IPR000832
G-protein-coupled receptors, GPCRs, constitute a vast protein family that encompasses a wide range of functions (including various autocrine, paracrine and endocrine processes). They show considerable diversity at the sequence level, on the basis of which they can be separated into distinct groups. We use the term clan to describe the GPCRs, as they embrace a group of families for which there are indications of evolutionary relationship, but between which there is no statistically significant similarity in sequence [PUBMED:8170923]. The currently known clan members include the rhodopsin-like GPCRs, the secretin-like GPCRs, the cAMP receptors, the fungal mating pheromone receptors, and the metabotropic glutamate receptor family. There is a specialised database for GPCRs (http://www.gpcr.org/7tm/).
The secretin-like GPCRs include secretin [PUBMED:1646711], calcitonin [PUBMED:1658940], parathyroid hormone/parathyroid hormone-related peptides [PUBMED:1658941] and vasoactive intestinal peptide [PUBMED:1314625], all of which activate adenylyl cyclase and the phosphatidyl-inositol-calcium pathway. These receptors contain seven transmembrane regions, in a manner reminiscent of the rhodopsins and other receptors believed to interact with G-proteins (however there is no significant sequence identity between these families, the secretin-like receptors thus bear their own unique '7TM' signature). Their N terminus is probably located on the extracellular side of the membrane and potentially glycosylated. This N-terminal region contains a long conserved region which allow the binding of large peptidic ligand such as glucagon, secretin, VIP and PACAP; this region contains five conserved cysteines residues which could be involved in disulphide bond. The C-terminal region of these receptor is probably cytoplasmic. Every receptor gene in this family is encoded on multiple exons, and several of these genes are alternatively spliced to yield functionally distinct products.
Gene Ontology
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
| Cellular component | integral to membrane (GO:0016021) |
| Molecular function | G-protein coupled receptor activity (GO:0004930) |
| Biological process | G-protein coupled receptor signaling pathway (GO:0007186) |
Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Pfam Clan
This family is a member of clan GPCR_A (CL0192), which contains the following 35 members:
7TM-7TMR_HD 7tm_1 7tm_2 7tm_4 7TM_GPCR_Sra 7TM_GPCR_Srab 7TM_GPCR_Srb 7TM_GPCR_Srbc 7TM_GPCR_Srd 7TM_GPCR_Srh 7TM_GPCR_Sri 7TM_GPCR_Srj 7TM_GPCR_Srsx 7TM_GPCR_Srt 7TM_GPCR_Sru 7TM_GPCR_Srv 7TM_GPCR_Srw 7TM_GPCR_Srx 7TM_GPCR_Srz 7TM_GPCR_Str Bac_rhodopsin Dicty_CAR DUF1182 DUF621 Frizzled Git3 Git3_C GpcrRhopsn4 Lung_7-TM_R Ocular_alb Serpentine_r_xa Sre Srg TAS2R V1RAlignments
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...
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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
| Seed (31) |
Full (4718) |
Representative proteomes | NCBI (4248) |
Meta (5) |
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| RP15 (852) |
RP35 (1057) |
RP55 (1672) |
RP75 (2544) |
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| PP/heatmap | 1 | |||||||
| Pfam viewer | ||||||||
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key:
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We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.
| Seed (31) |
Full (4718) |
Representative proteomes | NCBI (4248) |
Meta (5) |
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| RP15 (852) |
RP35 (1057) |
RP55 (1672) |
RP75 (2544) |
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| Raw Stockholm | ||||||||
| Gzipped | ||||||||
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
External links
MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.
HMM logo
HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...
Trees
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
Note: You can also download the data file for the tree.
Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
Curation
| Seed source: | Prosite |
| Previous IDs: | none |
| Type: | Family |
| Author: | Sonnhammer ELL |
| Number in seed: | 31 |
| Number in full: | 4718 |
| Average length of the domain: | 225.10 aa |
| Average identity of full alignment: | 22 % |
| Average coverage of the sequence by the domain: | 28.73 % |
HMM information
| HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
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| Model details: |
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| Model length: | 243 | ||||||||||||
| Family (HMM) version: | 19 | ||||||||||||
| Download: | download the raw HMM for this family |
Species distribution
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Structures
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the 7tm_2 domain has been found. There are 3 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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Archea
Eukaryota
Bacteria
Other sequences
Viruses
Unclassified
Viroids
Unclassified sequence