Myocardin-related transcription factors regulate the Cdk5/Pctaire1 kinase cascade to control neurite outgrowth, neuronal migration and brain development.
Numerous motile cell functions depend on signaling from the cytoskeleton to the nucleus. Myocardin-related transcription factors (MRTFs) translocate to the nucleus in response to actin polymerization and cooperate with serum response factor (Srf) to regulate the expression of genes encoding actin and other components of the cytoskeleton. Here, we show that MRTF-A (Mkl1) and MRTF-B (Mkl2) redundantly control neuronal migration and neurite outgrowth during mouse brain development. Conditional deletion of the genes encoding these Srf coactivators disrupts the formation of multiple brain structures, reflecting a failure in neuronal actin polymerization and cytoskeletal assembly. These abnormalities were accompanied by dysregulation of the actin-severing protein gelsolin and Pctaire1 (Cdk16) kinase, which cooperates with Cdk5 to initiate a kinase cascade that governs cytoskeletal rearrangements essential for neuron migration and neurite outgrowth. Thus, the MRTF/Srf partnership interlinks two key signaling pathways that control actin treadmilling and neuronal maturation, thereby fulfilling a regulatory loop that couples cytoskeletal dynamics to nuclear gene transcription during brain development.
Department of Molecular Biology, UT Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA.
Mayssa H
MH
Mokalled
Aaron
A
Johnson
Yuri
Y
Kim
Jiyeon
J
Oh
Eric N
EN
Olson
D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002465:Cell Movement / Q000235:genetics / Q000502:physiology*; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D051360:Cyclin-Dependent Kinase 5 / Q000235:genetics / Q000378:metabolism; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D016501:Neurites / Q000378:metabolism; D055495:Neurogenesis; D009687:Nuclear Proteins; D010770:Phosphotransferases / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D026362:Serum Response Factor / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D000099251:Myocardin
D000199:Actins; D051360:Cyclin-Dependent Kinase 5; D008840:Microfilament Proteins; D009687:Nuclear Proteins; D010770:Phosphotransferases; D026362:Serum Response Factor; D015534:Trans-Activators; D014157:Transcription Factors; D000099251:Myocardin