Human cathepsin B-encoding cDNAs: sequence variations in the 3'-untranslated region.
We have isolated two cathepsin B (CTSB)-encoding cDNAs, hCBF1 and hCBF2, from a normal human embryonic fibroblast library. These clones demonstrate 98% identity to overlapping regions of published human hepatoma and kidney CTSB cDNAs, but show some interesting differences from the published sequences in the 3'-untranslated region (3'-UTR). Both hCBF1 and hCBF2 contain a 10-bp insertion in the 3'-UTR that may permit formation of a highly stable stem-loop structure not present in mRNAs without this insertion. Our hCBF1 cDNA also contains a 1019-bp extension of the 3'-UTR sequence that resembles the long 3'-UTR reported for murine CTSB cDNAs. Probes unique to this 3'-UTR extension hybridize to 4.0- and 1.7-kb CTSB RNAs on Northern blots, but not to the major 2.2-kb mRNA transcript. Our data reveal variations in normal human CTSB transcripts that result from differences in the length of the 3'-UTR, as well as the presence or absence of a stem-loop stabilizing sequence.
Tam
S W
SW
Department of Pathology, Boston University School of Medicine, MA 02118.
Cote-Paulino
L R
LR
Peak
D A
DA
Sheahan
K
K
Murnane
M J
MJ
D001483:Base Sequence; D015152:Blotting, Northern; D002401:Cathepsin B / Q000235:genetics*; D015342:DNA Probes; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification*; D005347:Fibroblasts / Q000737:chemistry; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D015342:DNA Probes; D018076:DNA, Complementary; D012313:RNA; D002401:Cathepsin B