Sequence of a cDNA clone encoding human preproinsulin-like growth factor II

Area of Science:

• Biochemistry
• Molecular Biology
• Endocrinology

Background:

• Insulin-like growth factors (IGF) I and II are crucial serum proteins for fetal and postnatal growth.
• IGF-I levels fluctuate with puberty and reflect growth hormone status, while IGF-II levels remain stable.
• Understanding IGF biosynthesis is key to their roles in development and cancer.

Purpose of the Study:

• To investigate the biosynthesis of IGF-I and IGF-II.
• To elucidate the roles of IGFs in normal development and tumorigenesis.
• To isolate and sequence cDNAs encoding IGF precursors from human liver mRNA.

Main Methods:

• Isolation of cDNAs from adult human liver mRNA.
• Sequencing of isolated cDNAs to determine precursor protein sequences.
• Analysis of cDNA sequences to identify encoding proteins.

Main Results:

• Successfully isolated and sequenced cDNAs encoding precursors for IGF-I and IGF-II.
• Reported the sequence of a cDNA encoding a 180-amino acid precursor for IGF-II.
• Confirmed liver as a site of IGF synthesis.

Conclusions:

• The study provides foundational genetic sequences for IGF precursors.
• This research is a critical first step towards understanding IGF functions in growth and disease.
• The findings pave the way for further investigation into IGF-mediated biological processes.