Dataset Information

Differential expression of two distinct forms of mRNA encoding members of a dipeptidyl aminopeptidase family.

ABSTRACT: We have identified two cDNAs encoding dipeptidyl aminopeptidase-like proteins (DPPXs) in both bovine and rat brains that have different N-terminal cytoplasmic domains but share an identical transmembrane domain and a long C-terminal extracellular domain. In both species, one of the cDNAs encodes a protein (designated DPPX-S) of 803 amino acid residues with a short cytoplasmic domain of 32 amino acids, and the other cDNA encodes a protein (designated DPPX-L) with a longer cytoplasmic domain--the bovine cDNA encodes 92 amino acids and the rat cDNA encodes 88 amino acids. The membrane topology of DPPX-S and -L is similar to that of other transmembrane peptidases, and DPPX-S share approximately 30% identity and 50% similarity with reported yeast and rat liver dipeptidyl aminopeptidase amino acid sequences, suggesting that DPPX is a member of the dipeptidyl aminopeptidase family. DPPX-S mRNA is expressed in brain and some peripheral tissues including kidney, ovary, and testis; in contrast, DPPX-L mRNA is expressed almost exclusively in brain. No transcripts for either form are found in heart, liver, or spleen. In situ hybridization studies show that the two transcripts have different distributions in the brain. DPPX-L mRNA is expressed in limited regions of brain with the highest level of expression in the medial habenula. More widespread expression is seen for DPPX-S mRNA. The differential distribution of mRNAs for the DPPX-S and -L suggests that these proteins are involved in the metabolism of certain localized peptides and that the cytoplasmic domain may play a key role in determining the physiological specificity of DPPX.

SUBMITTER: Wada K

PROVIDER: S-EPMC48203 | biostudies-other | 1992 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Differential expression of two distinct forms of mRNA encoding members of a dipeptidyl aminopeptidase family.

Wada K K Yokotani N N Hunter C C Doi K K Wenthold R J RJ Shimasaki S S

Proceedings of the National Academy of Sciences of the United States of America 19920101 1

We have identified two cDNAs encoding dipeptidyl aminopeptidase-like proteins (DPPXs) in both bovine and rat brains that have different N-terminal cytoplasmic domains but share an identical transmembrane domain and a long C-terminal extracellular domain. In both species, one of the cDNAs encodes a protein (designated DPPX-S) of 803 amino acid residues with a short cytoplasmic domain of 32 amino acids, and the other cDNA encodes a protein (designated DPPX-L) with a longer cytoplasmic domain--the ...[more]

PMID: 1729689

Similar Datasets

Project description:As one of the major, highly conserved catabolic pathways, autophagy delivers cytosolic components to lysosomes for degradation. It is essential for development, cellular homeostasis, and coping with stress. Reduced autophagy increases susceptibility to protein aggregation diseases and leads to phenotypes associated with aging. Of the three major forms of autophagy, macroautophagy (MA) can degrade organelles or aggregated proteins, and chaperone-mediated autophagy is specific for soluble proteins containing KFERQ-related targeting motifs. During endosomal microautophagy (eMI), cytoplasmic proteins are engulfed into late endosomes in an ESCRT machinery-dependent manner. eMI can be KFERQ-specific or occur in bulk and be induced by prolonged starvation. Its physiological regulation and function, however, are not understood. Here, we show that eMI in the Drosophila fat body, akin to the mammalian liver, is induced upon oxidative or genotoxic stress in an ESCRT and partially Hsc70-4-dependent manner. Interestingly, eMI activation is selective, as ER stress fails to elicit a response. Intriguingly, we find that reducing MA leads to a compensatory enhancement of eMI, suggesting a tight interplay between these degradative processes. Furthermore, we show that mutations in DNA damage response genes are sufficient to trigger eMI and that the response to oxidative stress is under the control of MAPK/JNK signaling. Our data suggest that, controlled by various signaling pathways, eMI allows an organ to react and adapt to specific types of stress and is thus likely critical to prevent disease.Abbreviations: Atg: autophagy-related; CMA: chaperone-mediated autophagy; DDR: DNA damage repair; Df: deficiency (deletion); (E)GFP: (enhanced) green fluorescent protein; eMI: endosomal microautophagy; ER: endoplasmatic reticulum; ESCRT: endosomal sorting complexes required for transport; Eto: etoposide; FLP: flipase; Hsc: heat shock cognate protein; LAMP2A: lysosomal-associated membrane protein 2A; LE: late endosome; MA: macroautophagy; MI: microautophagy; MVB: multivesicular body; PA: photoactivatable; Para: paraquat; ROS: reactive oxygen species; SEM: standard error of means; Tor: target of rapamycin [serine/threonine kinase]; UPR: unfolded protein response; Vps: vacuolar protein sorting.

Project description:BackgroundAmastins are surface glycoproteins (approximately 180 residues long) initially described in Trypanosoma cruzi as particularly abundant during the amastigote stage of this protozoan parasite. Subsequently, they have been found to be encoded by large gene families also present in the genomes of several species of Leishmania and in other Trypanosomatids. Although most amastin genes are organized in clusters associated with tuzin genes and are up-regulated in the intracellular stage of T. cruzi and Leishmania spp, distinct genomic organizations and mRNA expression patterns have also been reported.ResultsBased on the analysis of the complete genome sequences of two T. cruzi strains, we identified a total of 14 copies of amastin genes in T. cruzi and showed that they belong to two of the four previously described amastin subfamilies. Whereas δ-amastin genes are organized in two or more clusters with alternating copies of tuzin genes, the two copies of β-amastins are linked together in a distinct chromosome. Most T. cruzi amastins have similar surface localization as determined by confocal microscopy and western blot analyses. Transcript levels for δ-amastins were found to be up-regulated in amastigotes from several T. cruzi strains, except in the G strain, which is known to have low infection capacity. In contrast, in all strains analysed, β-amastin transcripts are more abundant in epimastigotes, the stage found in the insect vector.ConclusionsHere we showed that not only the number and diversity of T. cruzi amastin genes is larger than what has been predicted, but also their mode of expression during the parasite life cycle is more complex. Although most T. cruzi amastins have a similar surface localization, only δ-amastin genes have their expression up-regulated in amastigotes. The results showing that a sub-group of this family is up-regulated in epimastigotes, suggest that, in addition of their role in intracellular amastigotes, T. cruzi amastins may also serve important functions during the insect stage of the parasite life cycle. Most importantly, evidence for their role as virulence factors was also unveiled from the data showing that δ-amastin expression is down regulated in a strain presenting low infection capacity.

Dataset Information

Differential expression of two distinct forms of mRNA encoding members of a dipeptidyl aminopeptidase family.

Publications

Differential expression of two distinct forms of mRNA encoding members of a dipeptidyl aminopeptidase family.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets