scholarly journals Independent changes in type I and type II receptors for transforming growth factor beta induced by bone morphogenetic protein 2 parallel expression of the osteoblast phenotype.

1995 ◽  
Vol 15 (6) ◽  
pp. 3273-3281 ◽  
Author(s):  
M Centrella ◽  
S Casinghino ◽  
J Kim ◽  
T Pham ◽  
V Rosen ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Bone Cells ◽  
Bone Morphogenetic Protein 2 ◽  
Type I ◽  
Type Ii ◽  
Tgf Beta ◽  
Biochemical Activity ◽  
Morphogenetic Protein ◽  
Growth Factor Beta

Transforming growth factor beta (TGF-beta), a potent regulator of bone formation, has bifunctional effects on osteoblast replication and biochemical activity that appear differentiation dependent. We now show that cell surface binding sites for TGF-beta vary markedly among fibroblasts, bone-derived cells, and highly differentiated osteosarcoma cultures from fetal rats. Expression of betaglycan and type II receptors decline relative to type I receptor expression in parallel with an increase in osteoblast-like activity, predicting that the ratio among various TGF-beta binding sites could influence how its signals are perceived. Bone morphogenetic protein 2 (BMP-2), which induces osteoblast function, does not alter TGF-beta binding or biochemical activity in fibroblasts and has only small effects in less differentiated bone cells. In contrast, BMP-2 rapidly reduces TGF-beta binding to betaglycan and type II receptors in osteoblast-enriched primary cell cultures and increases its relative binding to type I receptors in these cells and in ROS 17/2.8 cultures. Pretreatment with BMP-2 diminishes TGF-beta-induced DNA synthesis in osteoblast-enriched cultures but synergistically enhances its stimulatory effects on either collagen synthesis or alkaline phosphatase activity, depending on the present state of bone cell differentiation. Therefore, BMP-2 shifts the TGF-beta binding profile on bone cells in ways that are consistent with progressive expression of osteoblast phenotype, and these changes distinguish the biochemical effects mediated by each receptor. Our observations indicate specific stepwise actions by TGF-beta family members during osteoblast differentiation, developing in part from changes imprinted by BMP-2 on TGF-beta receptor stoichiometry.

scholarly journals mRNA expression of type I and type II receptors for activin, transforming growth factor-beta, and bone morphogenetic protein in the murine erythroleukemic cell line, F5-5.fl

2000 ◽  
pp. 705-710 ◽  
Author(s):  
H Machida ◽  
K Ogawa ◽  
M Funaba ◽  
T Mizutani ◽  
M Tsujimoto
Keyword(s):  
Growth Factor ◽  
Mrna Expression ◽  
Bone Morphogenetic Protein ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Type I ◽  
Type Ii ◽  
Tgf Beta ◽  
Morphogenetic Protein ◽  
Growth Factor Beta

OBJECTIVE: Intracellular signaling of activin and transforming growth factor-beta (TGF-beta) is thought to be mediated by the same molecules (Smad2/3 and Smad4). Although differentiation of murine erythroleukemia F5-5.fl cells is induced by activin, it is not induced by TGF-beta, suggesting that at some point TGF-beta signaling is defective. The aim of this study was to investigate the unresponsiveness of F5-5.fl cells to TGF-beta. DESIGN: mRNA expression of ligands, receptors, and signal mediators for the TGF-beta family was examined in F5-5.fl cells using RT-PCR. RESULTS: Activin induced erythrodifferentiation of F5-5.fl cells in a dose-dependent manner. Neither TGF-beta1 nor bone morphogenetic protein (BMP)-4 affected the differentiation of F5-5.fl cells in the presence or absence of activin. Although mRNAs of TGF-betas (TGF-beta1, TGF-beta2 and TGF-beta3) were detected, those of inhibin/activin (alpha-, betaA- and betaB-subunits) and BMPs (BMP-2, BMP-4 and BMP-7) could not be detected in the cells, suggesting that neither activins nor BMPs are produced in F5-5.fl cells. The expression of both type I (ALK-4/ActRIB) and type II (ActRII) receptors for activin was detected in F5-5.fl cells. In contrast, while the expression of type I receptor for TGF-beta (ALK-5/TbetaRI) was detected, that of type II receptor (TbetaRII) was not. The mRNA of all Smads examined was detected in F5-5.fl cells. CONCLUSIONS: A defect in the type II receptor might cause unresponsiveness to TGF-beta in F5-5.fl cells. An erythrodifferentiation assay using F5-5.fl cells would be useful for measuring net activin activity because it would not be necessary to consider endogenous activins and BMPs.

scholarly journals Two distinct transmembrane serine/threonine kinases from Drosophila melanogaster form an activin receptor complex.

1994 ◽  
Vol 14 (2) ◽  
pp. 944-950 ◽  
Author(s):  
J L Wrana ◽  
H Tran ◽  
L Attisano ◽  
K Arora ◽  
S R Childs ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Transmembrane Protein ◽  
Bone Morphogenetic Protein 2 ◽  
Type I ◽  
Type Ii ◽  
Tgf Beta ◽  
Activin Receptor ◽  
Domain Of Unknown Function

A transmembrane protein serine/threonine kinase, Atr-I, that is structurally related to receptors for members of the transforming growth factor-beta (TGF-beta) family has been cloned from Drosophila melanogaster. The spacing of extracellular cysteines and the cytoplasmic domain of Atr-I resemble most closely those of the recently described mammalian type I receptors for TGF-beta and activin. When expressed alone in test cells, Atr-I is unable to bind TGF-beta, activin, or bone morphogenetic protein 2. However, Atr-I binds activin efficiently when coexpressed with the distantly related Drosophila activin receptor Atr-II, with which it forms a heteromeric complex. Atr-I can also bind activin in concert with mammalian activin type II receptors. Two alternative forms of Atr-I have been identified that differ in an ectodomain region encompassing the cysteine box motif characteristic of receptors in this family. Comparison of Atr-I with other type I receptors reveals the presence of a characteristic 30-amino-acid domain immediately upstream of the kinase region in all these receptors. This domain, of unknown function, contains a repeated Gly-Ser sequence and is therefore referred to as the GS domain. Maternal Atr-I transcripts are abundant in the oocyte and widespread during embryo development and in the imaginal discs of the larva. The structural properties, binding specificity, and dependence on type II receptors define Atr-I as an activin type I receptor from D. melanogaster. These results indicate that the heteromeric kinase structure is a general feature of this receptor family.

Type I receptors specify growth-inhibitory and transcriptional responses to transforming growth factor beta and activin

1994 ◽  
Vol 14 (6) ◽  
pp. 3810-3821
Author(s):  
J Cárcamo ◽  
F M Weis ◽  
F Ventura ◽  
R Wieser ◽  
J L Wrana ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Amino Acid Sequence Identity ◽  
Transforming Growth Factor ◽  
Type I ◽  
Type Ii ◽  
Tgf Beta ◽  
Transcriptional Responses ◽  
Receptor Complexes ◽  
Growth Inhibitory ◽  
Growth Factor Beta

Transforming growth factor beta (TGF-beta) and activin bind to receptor complexes that contain two distantly related transmembrane serine/threonine kinases known as receptor types I and II. The type II receptors determine ligand binding specificity, and each interacts with a distinct repertoire of type I receptors. Here we identify a new type I receptor for activin, ActR-IB, whose kinase domain is nearly identical to that of the recently cloned TGF-beta type I receptor, T beta R-I. ActR-IB has the structural and binding properties of a type I receptor: it binds activin only in the presence of an activin type II receptor and forms a heteromeric noncovalent complex with activin type II receptors. In Mv1Lu lung epithelial cells, ActR-IB and T beta R-I signal a common set of growth-inhibitory and transcriptional responses in association with their corresponding ligands and type II receptors. The transcriptional responses include elevated expression of fibronectin and plasminogen activator inhibitor 1. Although T beta R-I and ActR-IB are nearly identical in their kinase domains (90% amino acid sequence identity), their corresponding type II receptor kinase domains are very different from each other (42% amino acid sequence identity). Therefore, signaling of a specific set of responses by TGF-beta and activin correlates with the presence of similar type I kinases in their complex. Indeed, other TGF-beta and activin type I receptors (TSR-I and ActR-I) whose kinase domains significantly diverge from those of T beta R-I and ActR-IB do not substitute as mediators of these growth-inhibitory and extracellular matrix transcriptional responses. Hence, we conclude that the type I receptor subunits are primary specifiers of signals sent by TGF-beta and activin receptor complexes.

scholarly journals Type I receptors specify growth-inhibitory and transcriptional responses to transforming growth factor beta and activin.

1994 ◽  
Vol 14 (6) ◽  
pp. 3810-3821 ◽  
Author(s):  
J Cárcamo ◽  
F M Weis ◽  
F Ventura ◽  
R Wieser ◽  
J L Wrana ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Amino Acid Sequence Identity ◽  
Transforming Growth Factor ◽  
Type I ◽  
Type Ii ◽  
Tgf Beta ◽  
Transcriptional Responses ◽  
Receptor Complexes ◽  
Growth Inhibitory ◽  
Growth Factor Beta

Transforming growth factor beta (TGF-beta) and activin bind to receptor complexes that contain two distantly related transmembrane serine/threonine kinases known as receptor types I and II. The type II receptors determine ligand binding specificity, and each interacts with a distinct repertoire of type I receptors. Here we identify a new type I receptor for activin, ActR-IB, whose kinase domain is nearly identical to that of the recently cloned TGF-beta type I receptor, T beta R-I. ActR-IB has the structural and binding properties of a type I receptor: it binds activin only in the presence of an activin type II receptor and forms a heteromeric noncovalent complex with activin type II receptors. In Mv1Lu lung epithelial cells, ActR-IB and T beta R-I signal a common set of growth-inhibitory and transcriptional responses in association with their corresponding ligands and type II receptors. The transcriptional responses include elevated expression of fibronectin and plasminogen activator inhibitor 1. Although T beta R-I and ActR-IB are nearly identical in their kinase domains (90% amino acid sequence identity), their corresponding type II receptor kinase domains are very different from each other (42% amino acid sequence identity). Therefore, signaling of a specific set of responses by TGF-beta and activin correlates with the presence of similar type I kinases in their complex. Indeed, other TGF-beta and activin type I receptors (TSR-I and ActR-I) whose kinase domains significantly diverge from those of T beta R-I and ActR-IB do not substitute as mediators of these growth-inhibitory and extracellular matrix transcriptional responses. Hence, we conclude that the type I receptor subunits are primary specifiers of signals sent by TGF-beta and activin receptor complexes.

Two distinct transmembrane serine/threonine kinases from Drosophila melanogaster form an activin receptor complex

1994 ◽  
Vol 14 (2) ◽  
pp. 944-950
Author(s):  
J L Wrana ◽  
H Tran ◽  
L Attisano ◽  
K Arora ◽  
S R Childs ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Transmembrane Protein ◽  
Bone Morphogenetic Protein 2 ◽  
Type I ◽  
Type Ii ◽  
Tgf Beta ◽  
Activin Receptor ◽  
Domain Of Unknown Function

A transmembrane protein serine/threonine kinase, Atr-I, that is structurally related to receptors for members of the transforming growth factor-beta (TGF-beta) family has been cloned from Drosophila melanogaster. The spacing of extracellular cysteines and the cytoplasmic domain of Atr-I resemble most closely those of the recently described mammalian type I receptors for TGF-beta and activin. When expressed alone in test cells, Atr-I is unable to bind TGF-beta, activin, or bone morphogenetic protein 2. However, Atr-I binds activin efficiently when coexpressed with the distantly related Drosophila activin receptor Atr-II, with which it forms a heteromeric complex. Atr-I can also bind activin in concert with mammalian activin type II receptors. Two alternative forms of Atr-I have been identified that differ in an ectodomain region encompassing the cysteine box motif characteristic of receptors in this family. Comparison of Atr-I with other type I receptors reveals the presence of a characteristic 30-amino-acid domain immediately upstream of the kinase region in all these receptors. This domain, of unknown function, contains a repeated Gly-Ser sequence and is therefore referred to as the GS domain. Maternal Atr-I transcripts are abundant in the oocyte and widespread during embryo development and in the imaginal discs of the larva. The structural properties, binding specificity, and dependence on type II receptors define Atr-I as an activin type I receptor from D. melanogaster. These results indicate that the heteromeric kinase structure is a general feature of this receptor family.

scholarly journals Formation of hetero-oligomeric complexes of type I and type II receptors for transforming growth factor-beta.

1994 ◽  
Vol 269 (31) ◽  
pp. 20172-20178 ◽  
Author(s):  
H. Yamashita ◽  
P. ten Dijke ◽  
P. Franzén ◽  
K. Miyazono ◽  
C.H. Heldin
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Type I ◽  
Type Ii ◽  
Growth Factor Beta
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