Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.1.26.4 (
RNase H
)
2,751
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Previous studies have revealed multiple size classes of rat
insulin-like growth factor-I
(
IGF-I
) of estimated size 7.5-7.0, 1.9-1.5, and 1.2-0.9 kilobases (kb). Available sequence information accounts for only 2.1 kb of the 7.5-7.0 kb
IGF-I
mRNAs. We used oligomer directed
ribonuclease H
(
RNase H
) mapping to define the extent to which the unknown sequence in the large molecular weight mRNAs lies 5' or 3' to known sequence. Rat liver polyadenylated RNAs were incubated with oligomer probes complementary to internal rat
IGF-I
precursor (E domain) coding sequences.
RNase H
was used to hydrolyze
IGF-I
mRNAs at the point of annealment with the oligomers. Resultant 5' and 3'-
IGF-I
mRNA fragments were analyzed on Northern blots. A probe specific for type 1 (class C) 5'-sequences (the most predominant of multiple 5'-sequence types found on rat
IGF-I
mRNAs) identifies intact
IGF-I
mRNAs of 7.5-7.0, 1.9-1.5 and 1.2-0.9 kb but, after oligomer directed RNase cleavage of these mRNAs, identified only a single
IGF-I
mRNA 5'-fragment. Major differences in the length of sequence 5' to the
IGF-I
coding sequence therefore, do not account for the multiple size classes of type 1 (class C)
IGF-I
mRNAs. The size of the 5'-fragment suggests that the extent of sequence 5' to the
IGF-I
coding sequence is 0.4-0.7 kb in type 1 (class C)
IGF-I
mRNAs. Identification of multiple 3'-fragments of
IGF-I
mRNAs demonstrated heterogeneity in the 3'-ends of rat
IGF-I
mRNAs.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The size heterogeneity of rat insulin-like growth factor-I mRNAs is due primarily to differences in the length of 3'-untranslated sequence. 256 Aug 8
