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Molecular cloning of the rat proteinase-activated receptor 4 (PAR4).

Hoogerwerf WA, Hellmich HL, Micci MA, Winston JH, Zou L, Pasricha PJ - BMC Mol. Biol. (2002)

Bottom Line: We have identified and characterized cDNA encoding the rat PAR4 homologue.PAR4 is expressed predominantly in the upper gastrointestinal tract.It is activated by trypsin, thrombin and its newly identified rat PAR4 specific activating peptide.

View Article: PubMed Central - HTML - PubMed

Affiliation: Enteric Neuromuscular Disorders and Pain Laboratory, Division of Gastroenterology and Hepatology, University of Texas Medical Branch, Galveston, TX, USA. wahooger@utmb.edu

ABSTRACT

Background: The proteinase-activated receptor 4 (PAR4) is a G-protein-coupled receptor activated by proteases such as thrombin and trypsin. Although activation of PAR4 has been shown to modulate rat gastrointestinal motility, the rat PAR4 sequence was unknown until now. This study aimed to identify the rat PAR4 cDNA.

Results: The cDNA coding for the rat PAR4 homologue was cloned from the duodenum. Northern blots demonstrated a 3.0 kb transcript in the duodenum. Protein homology with mouse and human counterparts was 90% and 75% respectively. PAR4 is expressed predominantly in the esophagus, stomach, duodenum and the spleen. When expressed in COS cells, PAR4 is activated by trypsin (1 nM), thrombin (50 nM), mouse PAR4 specific peptide (500 microM) and a putative rat PAR4 specific activating peptide (100 microM), as measured by intracellular Ca2+-changes.

Conclusions: We have identified and characterized cDNA encoding the rat PAR4 homologue. PAR4 is expressed predominantly in the upper gastrointestinal tract. It is activated by trypsin, thrombin and its newly identified rat PAR4 specific activating peptide.

No MeSH data available.


Related in: MedlinePlus

A Detection of PAR4 mRNA in rat tissues by RPA. Tissue sources are given at the top and the size of the protected fragment is given on the left. (CM, central marker; LES, lower esophageal sphincter; IAS, internal anal sphincter; DRG, dorsal root ganglia). B The PAR4/actin ratio suggests that PAR4 is predominantly expressed in the esophagus, LES, and the stomach.
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Figure 4: A Detection of PAR4 mRNA in rat tissues by RPA. Tissue sources are given at the top and the size of the protected fragment is given on the left. (CM, central marker; LES, lower esophageal sphincter; IAS, internal anal sphincter; DRG, dorsal root ganglia). B The PAR4/actin ratio suggests that PAR4 is predominantly expressed in the esophagus, LES, and the stomach.

Mentions: This corresponds in size to the predominant band previously described in human tissues. Expression in other tissues was measured by RPA (Figure 4).


Molecular cloning of the rat proteinase-activated receptor 4 (PAR4).

Hoogerwerf WA, Hellmich HL, Micci MA, Winston JH, Zou L, Pasricha PJ - BMC Mol. Biol. (2002)

A Detection of PAR4 mRNA in rat tissues by RPA. Tissue sources are given at the top and the size of the protected fragment is given on the left. (CM, central marker; LES, lower esophageal sphincter; IAS, internal anal sphincter; DRG, dorsal root ganglia). B The PAR4/actin ratio suggests that PAR4 is predominantly expressed in the esophagus, LES, and the stomach.
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Related In: Results  -  Collection

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Figure 4: A Detection of PAR4 mRNA in rat tissues by RPA. Tissue sources are given at the top and the size of the protected fragment is given on the left. (CM, central marker; LES, lower esophageal sphincter; IAS, internal anal sphincter; DRG, dorsal root ganglia). B The PAR4/actin ratio suggests that PAR4 is predominantly expressed in the esophagus, LES, and the stomach.
Mentions: This corresponds in size to the predominant band previously described in human tissues. Expression in other tissues was measured by RPA (Figure 4).

Bottom Line: We have identified and characterized cDNA encoding the rat PAR4 homologue.PAR4 is expressed predominantly in the upper gastrointestinal tract.It is activated by trypsin, thrombin and its newly identified rat PAR4 specific activating peptide.

View Article: PubMed Central - HTML - PubMed

Affiliation: Enteric Neuromuscular Disorders and Pain Laboratory, Division of Gastroenterology and Hepatology, University of Texas Medical Branch, Galveston, TX, USA. wahooger@utmb.edu

ABSTRACT

Background: The proteinase-activated receptor 4 (PAR4) is a G-protein-coupled receptor activated by proteases such as thrombin and trypsin. Although activation of PAR4 has been shown to modulate rat gastrointestinal motility, the rat PAR4 sequence was unknown until now. This study aimed to identify the rat PAR4 cDNA.

Results: The cDNA coding for the rat PAR4 homologue was cloned from the duodenum. Northern blots demonstrated a 3.0 kb transcript in the duodenum. Protein homology with mouse and human counterparts was 90% and 75% respectively. PAR4 is expressed predominantly in the esophagus, stomach, duodenum and the spleen. When expressed in COS cells, PAR4 is activated by trypsin (1 nM), thrombin (50 nM), mouse PAR4 specific peptide (500 microM) and a putative rat PAR4 specific activating peptide (100 microM), as measured by intracellular Ca2+-changes.

Conclusions: We have identified and characterized cDNA encoding the rat PAR4 homologue. PAR4 is expressed predominantly in the upper gastrointestinal tract. It is activated by trypsin, thrombin and its newly identified rat PAR4 specific activating peptide.

No MeSH data available.


Related in: MedlinePlus