Latent transforming growth factor beta-binding protein-3 and fibulin-1C interact with the extracellular domain of the heparin-binding EGF-like growth factor precursor.
BACKGROUND
The membrane-bound cell-surface precursor and soluble forms of heparin-binding epidermal growth factor-like growth factor (HB-EGF) contribute to many cellular developmental processes. The widespread occurrence of HB-EGF in cell and tissue types has led to observations of its role in such cellular and tissue events as tumor formation, cell migration, extracellular matrix formation, wound healing, and cell adherence. Several studies have reported the involvement of such extracellular matrix proteins as latent transforming growth factor beta-binding protein, TGF-beta, and fibulin-1 in some of these processes. To determine whether HB-EGF interacts with extracellular matrix proteins we used the extracellular domain of proHB-EGF in a yeast two-hybrid system to screen a monkey kidney cDNA library. cDNA clones containing nucleotide sequences encoding domains of two proteins were obtained and their derived amino acid sequences were evaluated.


RESULTS
From approximately equal to 3 x 10(6) screened monkey cDNA clones, cDNA clones were recovered that contained nucleotide sequences encoding domains of the monkey latent transforming growth factor-beta binding protein-3 (MkLTBP-3) and fibulin-1C protein. The amino acid sequence derived from the MkLTBP-3 gene shared 98.6% identity with human LTBP-3 and 86.7% identity with mouse LTBP-3 amino acid sequences. The amino acid sequence derived from the monkey fibulin-1C gene shared 97.2% identity with human fibulin-1C. Yeast two-hybrid screens indicate that LTBP-3 and fibulin-1C interact with proHB-EGF through their calcium-binding EGF-like modules.


CONCLUSIONS
The interactions of the extracellular domain of proHB-EGF with LTBP-3 and fibulin-1C suggest novel functions for HB-EGF between cell and tissue surfaces.
Brooke
Joanna S
JS
Dept of Biological Science, Depaul University, Chicago, Il 60614, USA. jbrooke@depaul.edu
Cha
Jeong-Heon
JH
Eidels
Leon
L
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D004815:Epidermal Growth Factor / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D015723:Gene Library; D006493:Heparin / Q000378:metabolism; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D037181:Lectins, C-Type; D051379:Mice; D008969:Molecular Sequence Data; D025941:Protein Interaction Mapping; D011498:Protein Precursors / Q000378:metabolism*; D017433:Protein Structure, Secondary / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D000099192:CD69 Antigens
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D004815:Epidermal Growth Factor; D016326:Extracellular Matrix Proteins; D006493:Heparin; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D037181:Lectins, C-Type; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D000099192:CD69 Antigens; C587883:HBEGF protein, human; C587884:Hbegf protein, mouse; C509038:LTBP3 protein, human; C509039:Ltbp3 protein, mouse; C060820:fibulin