title: Effect of thymosin beta15 on the branching of developing neurons.
abstract: The thymosin betas (Tbetas) are polypeptide regulators of actin dynamics that are critical for the growth and branching of neurites in developing neurons. We found that mRNAs for Tbeta4, Tbeta10, and Tbeta15 were highly expressed in the developing rat brain during neuritogenesis, supporting a role for the Tbetas in this process. Overexpression of the Tbetas increased the number of neurite branches per neuron in cultured hippocampal and cerebral cortex neurons, and Tbeta15 had the greatest effect. Actin binding activity appears to be essential for the branch-promoting activity of Tbetas because two mutants of Tbeta15 lacking monomeric actin binding activity failed to stimulate branch formation. We also found that transfection of siRNA against Tbeta15 reduced branching. Taken together, these data suggest that the three Tbetas, and especially Tbeta15, stimulate neurite branching during brain development.
authors.affiliation: Department of Anatomy and Division of Brain Korea 21 Biomedical Science, Korea University College of Medicine, 126-1, 5-Ka, Anam-Dong, Sungbuk-Gu, Seoul 136-705, Republic of Korea.
authors.forename: Jeehyung
authors.initials: J
authors.lastname: Choe
authors.forename: Woong
authors.initials: W
authors.lastname: Sun
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Yoon
authors.forename: Im Joo
authors.initials: IJ
authors.lastname: Rhyu
authors.forename: Eun Hae
authors.initials: EH
authors.lastname: Kim
authors.forename: Hyun
authors.initials: H
authors.lastname: Kim
mesh_terms: D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000166:cytology / Q000196:embryology*; D002478:Cells, Cultured; D008969:Molecular Sequence Data; D016501:Neurites / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013947:Thymosin / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000502:physiology*
chemical_list: D000199:Actins; C525161:thymosin beta15, rat; D013947:Thymosin