Glutaminyl Peptide Cyclotransferase (QPCT)

GCT; QC; EC; Glutaminyl Cyclase; Glutaminyl-tRNA cyclotransferase

SPN	P468
HGNC	9753
MGI	1917786
PubMed	23183267
RGD	621086
UniProt	Q16769
Wiki	QPCT

QPCT encodes human pituitary glutaminyl cyclase, which is responsible for the presence of pyroglutamyl residues in many neuroendocrine peptides. The amino acid sequence of this enzyme is 86% identical to that of bovine glutaminyl cyclase.

The deduced 361-amino acid protein has a calculated molecular mass of about 41 kD. It contains an N-terminal signal peptide region, several glycosylation and phosphorylation sites, and 2 cysteine residues conserved between the bovine and human enzymes. QPCT shares 86% overall sequence identity with the bovine homolog.Glutaminyl cyclase expression was upregulated in the cortices of individuals with Alzheimer disease and correlated with the appearance of pE-modified amyloid beta.

Reference

"Molecular cloning, sequence analysis and expression of human pituitary glutaminyl cyclase."
J. Mol. Endocrinol. 13:77-86(1994) [PubMed] [Europe PMC] [Abstract]

"Complete sequencing and characterization of 21,243 full-length human cDNAs."
Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract]

"Generation and annotation of the DNA sequences of human chromosomes 2 and 4."
Nature 434:724-731(2005) [PubMed] [Europe PMC] [Abstract]

"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]

"Glutaminyl cyclases unfold glutamyl cyclase activity under mild acid conditions."
FEBS Lett. 563:191-196(2004) [PubMed] [Europe PMC] [Abstract]

"Isolation of an isoenzyme of human glutaminyl cyclase: retention in the Golgi complex suggests involvement in the protein maturation machinery."
J. Mol. Biol. 379:966-980(2008) [PubMed] [Europe PMC] [Abstract]

"Crystal structures of human glutaminyl cyclase, an enzyme responsible for protein N-terminal pyroglutamate formation."
Proc. Natl. Acad. Sci. U.S.A. 102:13117-13122(2005) [PubMed] [Europe PMC] [Abstract]

"A conserved hydrogen-bond network in the catalytic centre of animal glutaminyl cyclases is critical for catalysis."
Biochem. J. 411:181-190(2008) [PubMed] [Europe PMC] [Abstract]

"Structures of glycosylated mammalian glutaminyl cyclases reveal conformational variability near the active center."
Biochemistry 50:6280-6288(2011) [PubMed] [Europe PMC] [Abstract]

"Structures of human Golgi-resident glutaminyl cyclase and its complexes with inhibitors reveal a large loop movement upon inhibitor binding."
J. Biol. Chem. 286:12439-12449(2011) [PubMed] [Europe PMC] [Abstract]