Identification of an alternative transcript of ABCA1 gene in different human cell types.
We have observed two ABCA1 gene transcripts in human skin fibroblasts. The RT-PCR amplification of the exon 3-exon 8 region generated a normal fragment (740 bp) and an abnormal fragment (600 bp) in a ratio ranging from 3:1 to 8/9:1. These two transcripts were present in other cells such as leukemia T-cells, endothelial and smooth muscle cells as well human hepatoma cells (HepG2). Restriction enzyme analysis and sequencing indicated that in the abnormal fragment exon 3 was followed by exon 5. The complete skipping of exon 4 leads to a premature stop and a predicted translation product of 74 amino acids. The ratio between the normal and alternative transcript is not affected by variation in ABCA1 gene expression induced by incubating cells in serum-free medium and in the presence of cholesterol. It is possible that this alternative splicing represents as mechanism that regulates the ABCA1 content in tissues.
Bellincampi
L
L
Dipartimento di Medicina Interna, Università di Roma "Tor Vergata,", Rome, Italy.
Simone
M L
ML
Motti
C
C
Cortese
C
C
Bernardini
S
S
Bertolini
S
S
Calandra
S
S
D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007438:Introns; D008075:Lipoproteins, HDL / Q000172:deficiency / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000378:metabolism
C577836:ABCA1 protein, human; D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; D017931:DNA Primers; D018076:DNA, Complementary; D008075:Lipoproteins, HDL; D012333:RNA, Messenger