Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
CHARACTERIZATION AND CHROMOSOMAL LOCALIZATION OF PTP-NP-2, A NEW ISOFORM OF PROTEIN-TYROSINE PHOSPHATASE-LIKE RECEPTOR, EXPRESSED ON SYNAPTIC BOUTONS
Autore:
JIANG SX; TULLOCH AG; KIM TA; FU YG; ROGERS R; GASKELL A; WHITE RA; AVRAHAM H; AVRAHAM S;
Indirizzi:
HARVARD UNIV,INST MED,BETH ISRAEL DEACONESS MED CTR,DIV EXPT MED & HEMATOL ONCOL BOSTON MA 02115 HARVARD UNIV,INST MED,BETH ISRAEL DEACONESS MED CTR,DIV EXPT MED & HEMATOL ONCOL BOSTON MA 02115 HARVARD UNIV,SCH PUBL HLTH,BIOMED IMAGING LAB BOSTON MA 02115 CHILDRENS MERCY HOSP,UMKC SCH MED,SECT MED GENET & MOL MED KANSAS CITY MO 64108
Titolo Testata:
Gene
fascicolo: 2, volume: 215, anno: 1998,
pagine: 345 - 359
SICI:
0378-1119(1998)215:2<345:CACLOP>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
DEPENDENT DIABETES-MELLITUS; CENTRAL-NERVOUS-SYSTEM; R-PTP-KAPPA; MOLECULAR-CLONING; HIPPOCAMPAL-NEURONS; HOMOPHILIC BINDING; CRYSTAL-STRUCTURE; AUTOANTIGEN; IDENTIFICATION; IA-2;
Keywords:
IA-2 FAMILY; NEURONS; SYNAPTIC BOUTONS; TYROSINE PHOSPHATASE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
51
Recensione:
Indirizzi per estratti:
Citazione:
S.X. Jiang et al., "CHARACTERIZATION AND CHROMOSOMAL LOCALIZATION OF PTP-NP-2, A NEW ISOFORM OF PROTEIN-TYROSINE PHOSPHATASE-LIKE RECEPTOR, EXPRESSED ON SYNAPTIC BOUTONS", Gene, 215(2), 1998, pp. 345-359

Abstract

Recently, there have been several reports describing the cloning and characterization of the novel family of protein tyrosine phosphatase-like receptor molecules (known as IA-2 and PTP-NP/PTP-IAR/IA-2 beta/phogrin), which may act as autoantigens in diabetes. Here, we report the molecular characterization and chromosomal localization of a new isoform of this family in brain termed PTP-NP-2 (for PTP-NP tyrosine phosphatase isoform), and its function in rat primary hippocampal neurons. PTP-NP-2 has 48% identity to IA-2. The principal difference between PTP-NP-2 and PTP-NP is a 17-amino-acid insert near the N-terminus of PTP-NP that is absent in PTP-NP-2. Genomic DNA analysis indicates that the17-amino-acid insert is coded by a separate exon, suggesting that both IA-2 beta and PTP-NP-2 are isoforms arising by alternate splicing ofthe same gene. Reverse transcriptase-PCR revealed that both isoforms are present in human SH-SY5Y neuroblastoma cells. PTP-NP-2 mRNA expression is highly restricted, with a 5.5-kb specific transcript in human fetal and adult brain and 5.5 and 3.8 kb in human adult pancreas. SH-SY5Y neuroblastoma and U87-MG glioblastoma cells showed specific transcripts of 5.5 and 3.8 kb, respectively, indicating the existence of several isoforms of this molecule in the nervous system. The human gene encoding PTP-NP-2 was assigned to human chromosome 7q22-qter using Southern blot analysis of genomic DNAs from rodent/human somatic hybrid cell lines. Confocal microscopy analyses of rat primary hippocampal neurons revealed that PTP-NP-2 is abundantly expressed on synaptic boutonsin primary neurons. Wild-type PTP-NP-2 showed no measurable tyrosine phosphatase activity using an in-vitro pNPP assay. Examination of the PTP-NP-2 catalytic consensus sequence revealed that this sequence differed from the typical tyrosine phosphatase-domain consensus sequence by an alanine to aspartate change (amino acid 930). Mutation of aspartate 930 to alanine produced a catalytically active enzyme, suggesting that native PTP-NP and its isoform PTP-NP-2 are catalytically inactive receptor protein tyrosine phosphatase homologues. Taken together, these results indicate that the tyrosine phosphatase PTP-NP-2 is a new isoform of PTP-NP tyrosine phosphatase, is expressed on synaptic boutons and may participate in the regulation of synaptic bouton endocytosis. (C) 1998 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 15/07/20 alle ore 20:33:06