Differential distributions of peptides in the epidermal growth factor family and phosphorylation of ErbB 1 receptor in adult rat brain.
Using two-site enzyme immunoassays, we measured protein levels of epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and heparin-binding epidermal growth factor (HB-EGF) in adult rat brain, and compared them with the phosphorylation levels of their receptor (ErbB 1). There were significant variations in the brain distributions of each ErbB 1 ligand. Among these ErbB 1 ligands, HB-EGF protein levels were higher than those of TGF alpha and those of EGF were the lowest. TGF alpha protein was relatively enriched in the midbrain regions, while HB-EGF levels were most abundant in the cerebellum. Protein distributions of the EGF family members were discordant with previously reported mRNA distributions. In addition, there was significant basal ErbB 1 phosphorylation detected with the largest amount of activation in the midbrain. These observations suggest that the activation of brain ErbB 1 involves post-translational regulation of multiple EGF family members in a region-specific manner.
Piao
Ying-Shan
YS
Division of Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan.
Iwakura
Yuriko
Y
Takei
Nobuyuki
N
Nawa
Hiroyuki
H
D000818:Animals; D001921:Brain / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D016211:Transforming Growth Factor alpha / Q000378:metabolism*
C587885:Hbegf protein, rat; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D066246:ErbB Receptors