[The short form of heparin-binding EGF-like growth factor. Part II].

The structure of monkey (Chlorocebus aethiops) heparin-binding EGF-like growth factor (HB-EGF) gene has been investigated in this work in comparison with the known structure of human gene. It was shown that HB-EGF short form (SF-HB-EGF) specific exon 3a is mapped between exons 3 and 4 at distance 700 b.p. from exon 4. In a number of human and simian cell lines the main part of SF-HB-EGF mRNA does not contain HB-EGF mRNA specific exons 4 and 5. In comparison with HB-EGF mRNA in SF-HB-EGF mRNA P-form, but not L-form of is predominant, and this mRNA encodes a polypeptide with changed propeptide structure. Labeled SF-HB-EGF competes with HB-EGF and EGF for binding sites at A431 cell surface, which may be due to interaction with specific receptor. All the data suggest a specific role of SF-HB-EGF in cellular signalization.