Junien JL

References (4)

Title : Cloning and characterization of dipeptidyl peptidase 10, a new member of an emerging subgroup of serine proteases - Qi_2003_Biochem.J_373_179
Author(s) : Qi SY , Riviere PJ , Trojnar J , Junien JL , Akinsanya KO
Ref : Biochemical Journal , 373 :179 , 2003
Abstract : Two dipeptidyl peptidase IV (DPPIV, DPP4)-related proteins, DPP8 and DPP9, have been identified recently [Abbott, Yu, Woollatt, Sutherland, McCaughan, and Gorrell (2000) Eur. J. Biochem. 267, 6140-6150; Olsen and Wagtmann (2002) Gene 299, 185-193; Qi, Akinsanya, Riviere, and Junien (2002) Patent application WO0231134]. In the present study, we describe the cloning of DPP10, a novel 796-amino-acid protein, with significant sequence identity to DPP4 (32%) and DPP6 (51%) respectively. We propose that DPP10 is a new member of the S9B serine proteases subfamily. The DPP10 gene is located on the long arm of chromosome 2 (2q12.3-2q14.2), close to the DPP4 (2q24.3) and FAP (2q23) genes. The active-site serine residue is replaced by a glycine residue in DPP10, resulting in the loss of DPP activity. The serine residue is also replaced in DPP6, which lacks peptidase activity. DPP8 and DPP9 share an identical active site with DPP4 (Gly-Trp-Ser-Tyr-Gly). In contrast with the previous results suggesting that DPP9 is inactive, we show that DPP9 is a DPP, hydrolysing Ala-Pro-(7-amino-4-methyl-coumarin) with similar pH-specificity and protease-inhibitor-sensitivity to those of DPP4 and DPP8. Northern-blot analysis shows that whereas DPP8 and DPP9 are widely expressed, DPP10 is expressed mainly in the brain and pancreas. DPP6, which has the highest amino acid identity with DPP10, has been shown previously [Nadal, Ozaita, Amarillo, de Miera, Ma, Mo, Goldberg, Misumi, Ikehara, Neubert et al. (2003) Neuron 37, 449-461] to associate with A-type K(+) channel subunits, modulating their transport and function in somatodendritic compartments of neurons. It is possible that DPP10 is involved in similar functions in the brain. Elucidation of the physiological or pathophysiological role of DPP8, DPP9 and DPP10 and characterization of their structure-function relationships will add impetus to the development of inhibitor molecules for pharmacological or therapeutic use.
ESTHER : Qi_2003_Biochem.J_373_179
PubMedSearch : Qi_2003_Biochem.J_373_179
PubMedID: 12662155
Gene_locus related to this paper: human-DPP8 , human-DPP9 , human-DPP10 , mouse-dpp9 , mouse-dpp10

Title : Dog gastric lipase: stimulation of its secretion in vivo and cytolocalization in mucous pit cells - Carriere_1992_Gastroenterology_102_1535
Author(s) : Carriere F , Raphel V , Moreau H , Bernadac A , Devaux MA , Grimaud R , Barrowman JA , Benicourt C , Junien JL , Laugier R , Verger R
Ref : Gastroenterology , 102 :1535 , 1992
Abstract : Dog gastric lipase (DGL) secretion is stimulated in vivo by urecholine, pentagastrin, histamine, 16,16-dimethyl prostaglandin E2, and secretin. Under fasting conditions, DGL is irreversibly inactivated by gastric acid below pH 1.5; consequently, DGL output can be underestimated. This problem has been resolved by buffering the acid or by using an antisecretory drug such as omeprazole during stimulation. There is a clear parallelism between the secretion of DGL and of gastric mucus. This observation led to the present investigation of the cellular localization of DGL using immunofluorescence techniques. Results showed that DGL is cytolocalized in mucous pit cells of gastric glands. Pepsinogen is found in chief cells. To the authors' knowledge, this is the first description of an enzyme (gastric lipase) secreted by mucous-type gastric cells. In contrast to other species, gastric lipase of the dog is located in cardiac, fundic, and antral mucosae.
ESTHER : Carriere_1992_Gastroenterology_102_1535
PubMedSearch : Carriere_1992_Gastroenterology_102_1535
PubMedID: 1568562

Title : Purification and biochemical characterization of dog gastric lipase - Carriere_1991_Eur.J.Biochem_202_75
Author(s) : Carriere F , Moreau H , Raphel V , Laugier R , Benicourt C , Junien JL , Verger R
Ref : European Journal of Biochemistry , 202 :75 , 1991
Abstract : A lipase was found to be present in dog stomach which appeared to be more abundant in the fundic than in the pyloric mucosa. Dog gastric lipase was extracted by soaking the gastric tissue and further purified after cation exchange, anion exchange and gel-filtration using fast protein liquid chromatography. The amino-acid composition, N-terminal amino-acid sequence, substrate specificity, interfacial and kinetic behavior and inactivation by sulfhydryl reagents were determined and compared with those of human and rabbit gastric lipases. We report for the first time that a gastric lipase is 13 times more active on long-chain than on short-chain triacylglycerols at pH 4.0, reaching a maximal specific activity of 950 U/mg on Intralipide emulsion.
ESTHER : Carriere_1991_Eur.J.Biochem_202_75
PubMedSearch : Carriere_1991_Eur.J.Biochem_202_75
PubMedID: 1935982
Gene_locus related to this paper: canfa-1lipg

Title : Purification, characterization and kinetic properties of the rabbit gastric lipase - Moreau_1988_Biochim.Biophys.Acta_960_286
Author(s) : Moreau H , Gargouri Y , Lecat D , Junien JL , Verger R
Ref : Biochimica & Biophysica Acta , 960 :286 , 1988
Abstract : Rabbit gastric lipase was purified from an acetonic powder of rabbit stomach fundus. 25 mg of pure rabbit gastric lipase (glycerol ester hydrolase, EC was obtained from 30 rabbit stomachs after ammonium sulfate fractionation, Sephadex G-100 gel filtration and cation exchange (mono S column) using a fast protein liquid chromatography (FPLC) system. The pure enzyme obtained was resistant to acidic pH conditions, and had specific activities of 1200, 850 and 280 U/mg, using, respectively, short- (tributyroylglycerol (TC4)), medium- (trioctanoyl- to tridecanoylglycerol (TC8-TC10)) and long-chain (soybean oil) triacylglycerols. The amino-acid composition was determined, and the first 30 N-terminal amino-acid residues were sequenced. Interfacial denaturation and catalytic properties on triacylglycerol emulsions were studied. Rabbit gastric lipase turned out to be structurally and kinetically very similar to human gastric lipase.
ESTHER : Moreau_1988_Biochim.Biophys.Acta_960_286
PubMedSearch : Moreau_1988_Biochim.Biophys.Acta_960_286
PubMedID: 3382677