Alternatively spliced transcripts of the thymus-specific protease PRSS16 are differentially expressed in human thymus.
The putative serine protease PRSS16 is abundantly expressed in the thymic cortex and the gene is encoded within the HLA I complex. Although its function is not yet defined, the very restricted expression points to a role in T-cell development in the thymus. In this study, we show that the PRSS16 mRNA is alternatively spliced to generate at least five transcripts. Apart from the full-length sequence, we found two other isoforms with all putative active site residues of the serine protease, suggesting that those variants may also be functional. Semi-quantitative analysis of the splice variants in different tissue samples revealed a strong correlation between the specific formation of alternatively spliced PRSS16 transcripts and the age and thymus pathology status of the donor. Newborn thymi express mostly the PRSS16-4 and -5 isoforms and lack the PRSS16-1 transcript, which appears around 2 years of age and stays until adulthood. Incidentally, thymi from myasthenia gravis (MG) patients with thymoma showed a marked decrease in the expression of the full-length PRSS16-1 and increased expression of the smaller isoforms. The data suggest a potential role of the PRSS16 isoforms in the postnatal morphogenesis of the thymus and in the thymus pathology related to MG.
Luther
C
C
Department of General Neurology, Hertie Institute for Clinical Brain Research, Tübingen University Hospital, 72076 Tübingen, Germany.
Wienhold
W
W
Oehlmann
R
R
Heinemann
M K
MK
Melms
A
A
Tolosa
E
E
D000328:Adult; D017398:Alternative Splicing / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000276:immunology; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics / Q000276:immunology; D009157:Myasthenia Gravis / Q000235:genetics / Q000276:immunology / Q000473:pathology; D012697:Serine Endopeptidases / Q000235:genetics* / Q000276:immunology; D013950:Thymus Gland / Q000254:growth & development / Q000276:immunology* / Q000473:pathology
D007527:Isoenzymes; C472502:PRSS16 protein, human; D012697:Serine Endopeptidases