Abstract

The dimeric Gh protein is comprised of α (tissue transglutaminase) and β (Calreticulin) subunits and known to be associated with FSH-, oxytocin-, or epinephrine-receptors/functions in their respective target cells. After establishing the FSH-induced activation of Gαh/phospholipase C (PLC)-δ1 pathway in rat Sertoli cells (SCs), we have attempted to identify a possible Gαh-coupled novel FSH receptor (FSH-R). Remarkably, a protein with approximately 240-kDa molecular mass was coimmunoprecipitated with Gαh in the fractionated membrane proteins of rat SCs. The protein was identified as myosin heavy polypeptide 9 (MyH9) by mass spectrometric analysis and immunoblotting. In addition, immunoprecipitation analysis reveals that MyH9 is constitutively associated with classical Gs-coupled FSH-R and inactive GDP-bound Gαh at resting state of rat SCs, but did not interact with FSH directly as judged by Far-Western analysis. Upon the stimulation of higher levels of extracellular FSH (>1000 IU/liter), classical FSH-R induces the phosphorylation of MyH9, the dissociation of active GTP-bound Gαh from FSH-R:MyH9 complexes, and the elicitation of Gαh/ PLC-δ1 pathway-dependent Ca2+-influx in rat SCs. Furthermore, the specific inhibition of MyH9 ATPase activity with Blebbistatin dose-dependently suppressed FSH-induced Gαh/PLC-δ1 signaling and Ca2+-influx, but not intracellular cAMP accumulation in rat SCs, implying that MyH9 mediates FSH-induced activation of Gαh/PLC-δ 1/IP3/Ca 2+-influx pathway in rat SCs. This is the first to demonstrate that the filament protein MyH9 constitutively forms a ternary complex with FSH-R and inactive GDP-bound Gαh. At higher FSH levels, this ternary complex executes an alternative signaling of classical Gs-coupled FSH-R through activating a Gs/cAMP-independent, Gαh/PLC-δ1 pathway in rat SCs. (Endocrinology 151: 876-885, 2010)

Original languageEnglish
Pages (from-to)876-885
Number of pages10
JournalEndocrinology
Volume151
Issue number3
DOIs
Publication statusPublished - Mar 2010

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Nonmuscle Myosin Type IIA
FSH Receptors
Sertoli Cells
Type C Phospholipases
Myosins
Transducers
Peptides
Proteins
Calreticulin
Endocrinology
Oxytocin
Guanosine Triphosphate
Immunoprecipitation
Immunoblotting
Adrenergic Receptors
Adenosine Triphosphatases
Membrane Proteins
Phosphorylation

ASJC Scopus subject areas

  • Endocrinology

Cite this

@article{a745cf18cc1c437e8e1313b9b3b026e4,
title = "Nonmuscle myosin IIA (myosin heavy polypeptide 9): A novel class of signal transducer mediating the activation of Gαh/phospholipase C-δ1 pathway",
abstract = "The dimeric Gh protein is comprised of α (tissue transglutaminase) and β (Calreticulin) subunits and known to be associated with FSH-, oxytocin-, or epinephrine-receptors/functions in their respective target cells. After establishing the FSH-induced activation of Gαh/phospholipase C (PLC)-δ1 pathway in rat Sertoli cells (SCs), we have attempted to identify a possible Gαh-coupled novel FSH receptor (FSH-R). Remarkably, a protein with approximately 240-kDa molecular mass was coimmunoprecipitated with Gαh in the fractionated membrane proteins of rat SCs. The protein was identified as myosin heavy polypeptide 9 (MyH9) by mass spectrometric analysis and immunoblotting. In addition, immunoprecipitation analysis reveals that MyH9 is constitutively associated with classical Gs-coupled FSH-R and inactive GDP-bound Gαh at resting state of rat SCs, but did not interact with FSH directly as judged by Far-Western analysis. Upon the stimulation of higher levels of extracellular FSH (>1000 IU/liter), classical FSH-R induces the phosphorylation of MyH9, the dissociation of active GTP-bound Gαh from FSH-R:MyH9 complexes, and the elicitation of Gαh/ PLC-δ1 pathway-dependent Ca2+-influx in rat SCs. Furthermore, the specific inhibition of MyH9 ATPase activity with Blebbistatin dose-dependently suppressed FSH-induced Gαh/PLC-δ1 signaling and Ca2+-influx, but not intracellular cAMP accumulation in rat SCs, implying that MyH9 mediates FSH-induced activation of Gαh/PLC-δ 1/IP3/Ca 2+-influx pathway in rat SCs. This is the first to demonstrate that the filament protein MyH9 constitutively forms a ternary complex with FSH-R and inactive GDP-bound Gαh. At higher FSH levels, this ternary complex executes an alternative signaling of classical Gs-coupled FSH-R through activating a Gs/cAMP-independent, Gαh/PLC-δ1 pathway in rat SCs. (Endocrinology 151: 876-885, 2010)",
author = "Lin, {Yuan Feng} and Yeh, {Tien Shun} and Chen, {Sung Fang} and Tsai, {Yu Hui} and Chou, {Chih Ming} and Yang, {Yi Yuan} and Huang, {Haw Ming}",
year = "2010",
month = "3",
doi = "10.1210/en.2009-0722",
language = "English",
volume = "151",
pages = "876--885",
journal = "Endocrinology",
issn = "0013-7227",
publisher = "The Endocrine Society",
number = "3",

}

TY - JOUR

T1 - Nonmuscle myosin IIA (myosin heavy polypeptide 9)

T2 - A novel class of signal transducer mediating the activation of Gαh/phospholipase C-δ1 pathway

AU - Lin, Yuan Feng

AU - Yeh, Tien Shun

AU - Chen, Sung Fang

AU - Tsai, Yu Hui

AU - Chou, Chih Ming

AU - Yang, Yi Yuan

AU - Huang, Haw Ming

PY - 2010/3

Y1 - 2010/3

N2 - The dimeric Gh protein is comprised of α (tissue transglutaminase) and β (Calreticulin) subunits and known to be associated with FSH-, oxytocin-, or epinephrine-receptors/functions in their respective target cells. After establishing the FSH-induced activation of Gαh/phospholipase C (PLC)-δ1 pathway in rat Sertoli cells (SCs), we have attempted to identify a possible Gαh-coupled novel FSH receptor (FSH-R). Remarkably, a protein with approximately 240-kDa molecular mass was coimmunoprecipitated with Gαh in the fractionated membrane proteins of rat SCs. The protein was identified as myosin heavy polypeptide 9 (MyH9) by mass spectrometric analysis and immunoblotting. In addition, immunoprecipitation analysis reveals that MyH9 is constitutively associated with classical Gs-coupled FSH-R and inactive GDP-bound Gαh at resting state of rat SCs, but did not interact with FSH directly as judged by Far-Western analysis. Upon the stimulation of higher levels of extracellular FSH (>1000 IU/liter), classical FSH-R induces the phosphorylation of MyH9, the dissociation of active GTP-bound Gαh from FSH-R:MyH9 complexes, and the elicitation of Gαh/ PLC-δ1 pathway-dependent Ca2+-influx in rat SCs. Furthermore, the specific inhibition of MyH9 ATPase activity with Blebbistatin dose-dependently suppressed FSH-induced Gαh/PLC-δ1 signaling and Ca2+-influx, but not intracellular cAMP accumulation in rat SCs, implying that MyH9 mediates FSH-induced activation of Gαh/PLC-δ 1/IP3/Ca 2+-influx pathway in rat SCs. This is the first to demonstrate that the filament protein MyH9 constitutively forms a ternary complex with FSH-R and inactive GDP-bound Gαh. At higher FSH levels, this ternary complex executes an alternative signaling of classical Gs-coupled FSH-R through activating a Gs/cAMP-independent, Gαh/PLC-δ1 pathway in rat SCs. (Endocrinology 151: 876-885, 2010)

AB - The dimeric Gh protein is comprised of α (tissue transglutaminase) and β (Calreticulin) subunits and known to be associated with FSH-, oxytocin-, or epinephrine-receptors/functions in their respective target cells. After establishing the FSH-induced activation of Gαh/phospholipase C (PLC)-δ1 pathway in rat Sertoli cells (SCs), we have attempted to identify a possible Gαh-coupled novel FSH receptor (FSH-R). Remarkably, a protein with approximately 240-kDa molecular mass was coimmunoprecipitated with Gαh in the fractionated membrane proteins of rat SCs. The protein was identified as myosin heavy polypeptide 9 (MyH9) by mass spectrometric analysis and immunoblotting. In addition, immunoprecipitation analysis reveals that MyH9 is constitutively associated with classical Gs-coupled FSH-R and inactive GDP-bound Gαh at resting state of rat SCs, but did not interact with FSH directly as judged by Far-Western analysis. Upon the stimulation of higher levels of extracellular FSH (>1000 IU/liter), classical FSH-R induces the phosphorylation of MyH9, the dissociation of active GTP-bound Gαh from FSH-R:MyH9 complexes, and the elicitation of Gαh/ PLC-δ1 pathway-dependent Ca2+-influx in rat SCs. Furthermore, the specific inhibition of MyH9 ATPase activity with Blebbistatin dose-dependently suppressed FSH-induced Gαh/PLC-δ1 signaling and Ca2+-influx, but not intracellular cAMP accumulation in rat SCs, implying that MyH9 mediates FSH-induced activation of Gαh/PLC-δ 1/IP3/Ca 2+-influx pathway in rat SCs. This is the first to demonstrate that the filament protein MyH9 constitutively forms a ternary complex with FSH-R and inactive GDP-bound Gαh. At higher FSH levels, this ternary complex executes an alternative signaling of classical Gs-coupled FSH-R through activating a Gs/cAMP-independent, Gαh/PLC-δ1 pathway in rat SCs. (Endocrinology 151: 876-885, 2010)

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JO - Endocrinology

JF - Endocrinology

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