Identification of genes downregulated in the thymus by cyclosporin-A: preliminary characterization of clone CSA-19.
Using a novel subtractive hybridization approach, we have identified a set of cDNA clones whose expression is downregulated in the thymus by cyclosporin-A (CsA). A number of regulated genes were identified, but the major focus of this report is the clone termed CsA-19. In the adult mouse, CsA-19 is expressed at high levels in lymphoid organs, particularly in secondary lymphoid organs such as lymph node and spleen. CsA-19 expression was also found to be regulated in the brain and liver during mouse development. The full length sequences of the murine and human CsA-19 cDNAs have been determined. Both are 700 nucleotides in length and encode a predicted product of 217 amino acids. Comparison of the full length cDNA sequences of murine and human CsA-19 reveal that they are greater than 91% conserved. At the predicted amino acid level the homology is even greater, with only two amino acid differences in 217 residues (99% identity). The high degree of homology between murine and human CsA-19 indicates that has there been strong evolutionary pressure to conserve the amino acid sequence of CsA-19, and suggests that CsA-19 may play a critical role both during embryogenesis and in mature lymphoid cells.
Fisicaro
N
N
Department of Clinical Immunology, St Vincent's Hospital, Fitzroy, Victoria, Australia.
Katerelos
M
M
Williams
J
J
Power
D
D
D'Apice
A
A
Pearse
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D001921:Brain / Q000196:embryology; D001923:Brain Chemistry; D002999:Clone Cells; D016572:Cyclosporine / Q000235:genetics / Q000494:pharmacology*; D018076:DNA, Complementary / Q000032:analysis; D015536:Down-Regulation / Q000235:genetics; D005314:Embryonic and Fetal Development / Q000187:drug effects; D005260:Female; D015723:Gene Library; D005796:Genes / Q000187:drug effects / Q000502:physiology*; D008099:Liver / Q000737:chemistry / Q000196:embryology; D051379:Mice; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D011247:Pregnancy; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects*
D018076:DNA, Complementary; D012333:RNA, Messenger; D016572:Cyclosporine