Cloning and expression of a cDNA coding for the human platelet-derived growth factor receptor: evidence for more than one receptor class.

Abstract

The complete nucleotide sequence of a cDNA encoding the human platelet-derived growth factor (PDGF) receptor is presented. The cDNA contains an open reading frame that codes for a protein of 1106 amino acids. Comparison to the mouse PDGF receptor reveals an overall amino acid sequence identity of 86%. This sequence identity rises to 98% in the cytoplasmic split tyrosine kinase domain. RNA blot hybridization analysis of poly(A)+ RNA from human dermal fibroblasts detects a major (=5.7 kb) and a minor (-4.8 kb) transcript using the cDNA as a probe. Baby hamster kidney cells, transfected with an expression vector containing the receptor cDNA, express an 190-kDa cell surface protein that is recognized by an anti-human PDGF receptor antibody. The recombinant PDGF receptor is functional in the transfected baby hamster kidney cells as demonstrated by ligand-induced phosphorylation of the receptor. Binding properties of the recombinant PDGF receptor were also assessed with pure preparations of BB and AB isoforms of PDGF (i.e., PDGF dimers composed of two B chains or an A and a B chain). Unlike human dermal fibroblasts, which bind both isoforms with high affinity, the transfected baby hamster kidney cells bind only the BB isoform of PDGF with high affinity. This observation is consistent with the existence of more than one PDGF receptor class.

Normal developing rat brain expresses a platelet-derived growth factor B chain (c-sis) mRNA truncated at the 5′ end

“…PDGF-B/c-sis probes are described below. The cDNA probes for human PDGFR-a and human PDGFR-b were the generous gifts of Dr T Matsui (Kobe University, Kobe, Japan; Matsui et al, 1989) and Dr RGK Gronwald (University of Washington, Seattle WA; Gronwald et al, 1988), respectively. Hybridization with a GAPDH probe was performed to control for sample loading.…”

Modification of PDGFα receptor expression or function alters the metastatic phenotype of 3LL cells

“…The a receptor recognizes with high a nity all three isoforms of PDGF whereas the b receptor binds PDGF-BB with high a nity and PDGF-AB with lower a nity but does not bind PDGF-AA (Heldin et al, 1988a). The cDNAs encoding a and b receptors of PDGF have been cloned and sequenced, and their primary structures have been shown to be structurally similar (Claesson-Welsh et al, 1988Do et al, 1992;Gronwald et al, 1988;Lee et al, 1990;Matsui et al, 1989;Yarden et al, 1986). The PDGF receptors, once thought to be restricted to anchorage-dependent cells of mesenchymal lineages such as ®broblasts, chondroblasts, and glial cells, have now been found in a variety of malignant tumor cells and numerous tumor cell lines (Do et al, 1992;FitzerAttas et al, 1993;Harsh et al, 1990;Heldin et al, 1988b;Iida et al, 1991;Leveen et al, 1990;Malik et al, 1991;Maxwell et al, 1990a, b;Wang et al, 1990).…”

Effect of the different dimeric forms of the platelet‐derived growth factor on cellular responses in mouse Swiss 3T3 fibroblasts

“…Whereas the responses induced by PDGF-AA are exclusi~gely mediated by the a-type receptors, those induced by PDGF-BB are mediated by both receptor types. It is still debated whether the AB heterodimer interacts with both receptors as some authors report [8,11,12] or whether it only interacts with the atype [9,10]. PDGF purified from human platelets contains a certain amount of PDGF-BB, in addition to the heterodimer [4] and thus we cannot distinguish between these two possibilities.…”

“…PDGF-AA is produced by different human tumoral cell lines [6,7]. Two types of highly homologous PDGF receptors have been identified and cloned [8][9][10][11][12][13]: an cr (or A)-type receptor which interacts with all three isoforms [12] and a ff (or B)-Correspondence address: E. Sturani, Department of General Physiology and Biochemistry, University of Milan, Via Celoria 26, 20133 Milan, Italy type receptor, which interacts with BB and AB dimers according to several authors [8,11,12] or only with BB according to other groups [9,10]. The two receptor types are structurally similar and are endowed with a protein tyrosine kinase domain [12,13].…”