Cloning and characterization of dipeptidyl peptidase 10, a new member of an emerging subgroup of serine proteases

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.

The amino terminus extension in the long dipeptidyl peptidase 9 isoform contains a nuclear localization signal targeting the active peptidase to the nucleus

“…the shorter version of DPP9 was initially identified by Olsen and Wagtmann [20]. Cloning and expression of this short DPP9 version (863 aa) in mammalian cell culture verified that DPP9-short is active and is localized to the cytosol [19,21]. Importantly, DPP9-short was recently purified from bovine testes, confirming the endogenous expression of this short DPP9 isoform [34].…”

“…60 % amino acid identity), are only emerging. Both peptidases are ubiquitously expressed on mRNa levels in various organs and tissues and cell lines [18][19][20][21][22]. Changes in the levels of these peptidases appear to be critical for cell survival, as both overexpression or application of DPP8/9 inhibitors lead to cell death in several cell lines [23][24][25].…”

Reversible Inactivation of Human Dipeptidyl Peptidases 8 and 9 by Oxidation

“…The ubiquitous expression of DP8 and DP9 [13,32,43] means that their regulation is probably important in many organs and biological processes. In addition to the immune system, skin may be an important location for this process; ultraviolet light produces sufficient reactive oxygen species and DP8 and DP9 are abundant in human skin (J.…”

Asp- and Glu-specific Novel Dipeptidyl Peptidase 11 of Porphyromonas gingivalis Ensures Utilization of Proteinaceous Energy Sources

“…Peptidyl dipeptidase, which liberates dipeptides from the C terminus of polypeptides, is localized in an intracellular compartment; thus, it seems to be driven for the breakdown of intracellular proteins (54). Among DPPs excluding peptidyl dipeptidase, eukaryotic DPP7 belongs to the DPPII family (50), and fibroblast activation protein ␣, DPP6 (eukaryote), and DPP8 -10 belong to the DPPIV family in respect to substrate specificity and sequence homology (49,(51)(52)(53)56). In summary, DPPI-DPPV are expressed in eukaryotic organisms, including fungi, mammals, fishes, and plants, whereas DPPIV, DPPVI, and DPP7 are known as bacterial enzymes.…”