Isolation and characterization of a transforming growth factor-$\beta$ Type II receptor cDNA from Xenopus laevis

Dhanasekaran, Saravana Mohan and Vempati, Uma Devi and Kondaiah, Paturu (2001) Isolation and characterization of a transforming growth factor-$\beta$ Type II receptor cDNA from Xenopus laevis. In: Gene, 263 (1-2). pp. 171-178.

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Abstract

Transforming Growth Factor-$\beta$ $(TGF-\beta)$ and their receptors have been characterized from many organisms. Two $TGF-\beta$ signaling receptors called Type I and II have been described for various ligands of the superfamily from organisms ranging from Drosophila to humans. In Xenopus laevis, $TGF-\beta 2$ and 5 have been reported and presumably, play important roles during early development. Several Type I and type II receptors for many ligands of the $TGF-\beta$ superfamily except $TGF-\beta$ type II receptor $(T \beta IIR)$, have been characterized in Xenopus laevis. A chemical cross linking experiment using iodinated $TGF-\beta 1$ and -$\beta 5$, revealed four specific binding proteins on XTC cells. In order to understand the $TGF-\beta$ involvement during Xenopus development, a $TGF-\beta$ type II receptor $(XT \beta IIR)$ has been isolated from a XTC cDNA library. $XT \beta IIR$ was a partial cDNA lacking a portion of the signal peptide. The sequence analysis and homology comparison with the human $T\beta IIR$ revealed 67% amino acid similarity in the extra cellular domain, 60% similarity in the transmembrane domain and 87% similarity in the cytoplasmic kinase domain, suggesting that $XT \beta IIR$ is a putative $TGF-\beta$ type II receptor. In addition, the consensus amino acid motif for serine threonine receptor kinases was also present. Further, a dominant negative expression construct lacking the cytoplasmic kinase domain (engineered with the signal peptide from human $TGF-\beta$ type II receptor), was able to abolish $TGF-\beta$ mediated induction of a luciferase reporter plasmid, in a transient cell transfection assay. This substantiates the notion that $XT \beta IIR$ cDNA can act as a receptor for $TGF-\beta$. RT-PCR analysis using RNA isolated from various developmental stages of Xenopus laevis revealed expression of this gene in all the early stages of development and in the adult organs, except in stages 46/48.

Item Type:	Journal Article
Publication:	Gene
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Development;Gene expression;TGF-β;XTC cells
Department/Centre:	Division of Biological Sciences > Molecular Reproduction, Development & Genetics
Date Deposited:	09 Oct 2007
Last Modified:	03 Feb 2012 06:11
URI:	http://eprints.iisc.ac.in/id/eprint/12175

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