An absolute requirement for both the type II and type I receptors, punt and thick veins, for Dpp signaling in vivo

Abstract

TGF beta elicits diverse cellular responses by signaling through receptor complexes formed by two distantly related transmembrane serine/threonine kinases called type II and type I receptors. Previous studies have indicated that the product of the Drosophila thick veins (tkv) gene is a type I receptor for decapentaplegic (dpp). Here, we show that the Drosophila gene punt encodes a homolog of a vertebrate type II receptor, and we demonstrate that punt, like tkv, is essential in vivo for dpp-dependent patterning processes. Because no dpp-related signalling is apparent in the absence of either the punt or tkv receptor, we infer that both receptors act in concert to transduce the dpp signal and that their functions cannot be replaced by the other extant type II and I receptors.

Schnurri interacts with Mad in a Dpp‐dependent manner

“…Punt is the type II receptor for Dpp, whereas Thick veins (Tkv) and Saxophone (Sax) are the type I receptors for it (Brummel et al 1994;Nellen et al 1994;Penton et al 1994;Xie et al 1994;Letsou et al 1995;Ruberte et al 1995). Sax also propagates signals of another Drosophila ligand, Screw (Scw) (Neul & Ferguson 1998;Nguyen et al 1998).…”

Stress signaling in Drosophila

“…Mutations in each gene lead to embryos with severe dorsal and anterior open cuticles indicative of a failure of DC and head involution. Loss of JNK pathway activity has (Glise & Noselli, 1997;Harden et al, 1995;1999) (Glise & Noselli, 1997;Harden et al, 1995;1999 (Padgett et al, 1987;Gelbart, 1987) (A olter et al, 1994;Brummel et al, 1994;Nellen et al, 1994;Penton et al, 1994) Ruberte et al, 1995) (Hudson et al, 1998) (Das et al, 1998;Hudson et al, 1998;Wisotzkey et al, 1998) Grieder et al, 1995;Staehling-Hampton et al, 1995) several consequences that contribute to a failure of DC. Mutant embryos exhibit a loss of dpp expression in LE cells without perturbing other elements of the dpp expression pattern (Glise and Noselli, 1997;Hou et al, 1997;Riesgo-Escovar and Hafen, 1997).…”

Role of Rho family GTPases in epithelial morphogenesis

“…Dpp is a secreted signaling molecule of the transforming growth factor ␤ (TGF-␤) family (Padgett et al 1987). Two Dpp receptors, Thick vein (Tkv) and Punt (Put), have been identified in flies, as well as a number of components acting downstream of these receptors, including Mad, Medea, and the Zinc finger protein Schnurri (Brummel et al 1994;Nellen et al 1994;Penton et al 1994;Grieder et al 1995;Letsou et al 1995;Ruberte et al 1995;Stronach and Perrimon 1999). Loss-of-function mutations in hep, bsk, DJun, and DFos all lead to severe DC defects that are characterized by a complete failure of the entire lateral ectoderm, including the LE cells, to elongate dorsally.…”