title: Arginyl aminopeptidase-like 1 (RNPEPL1) is an alternatively processed aminopeptidase with specificity for methionine, glutamine, and citrulline residues.
abstract: A previously uncharacterized member of the M1 family of zinc metallopeptidases, arginyl aminopeptidase-like 1 (RNPEPL1; EC 3.4.11.1), was cloned and expressed, and the recombinant enzyme characterized. RNPEPL1 was a broad specificity aminopeptidase with preference for a P1 methionine, glutamine, or citrulline residue, and exhibited a broad pH preference, with maximal activity observed between pH 6.6 and 8.0. The enzyme was inhibited by calcium ions but unaffected by chloride ions, and was insensitive to specific inhibitors of the closely-related arginyl aminopeptidase, indicating similarity to leukotriene A(4) hydrolase. RT-PCR analysis of RNPEPL1 expression revealed a ubiquitous tissue distribution, consistent with a general housekeeping function, but also revealed alternative splicing of the mRNA in all tissues examined. The inclusion of intron 5 was predicted to result in a truncated protein product, while an alternative 3' splice site of exon 9 of the reference sequence was predicted to result in the omission of a conserved eleven amino acid stretch from the C-terminal domain.
authors.affiliation: Department of Biology, Middle Tennessee State University, Murfreesboro, TN 37132, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Thompson
authors.forename: Karen A
authors.initials: KA
authors.lastname: Beasley
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Schmidt
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Seipelt
mesh_terms: D017398:Alternative Splicing; D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002384:Catalysis / Q000187:drug effects; D002460:Cell Line; D002956:Citrulline / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005091:Exons / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D008715:Methionine / Q000378:metabolism*; D011691:Puromycin / Q000494:pharmacology; D022821:RNA Splice Sites / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018411:Spodoptera; D013379:Substrate Specificity
chemical_list: D004791:Enzyme Inhibitors; D022821:RNA Splice Sites; D011994:Recombinant Proteins; D005973:Glutamine; D002956:Citrulline; D011691:Puromycin; D008715:Methionine; D000626:Aminopeptidases; C019721:aminopeptidase B; D002118:Calcium