title: Zebrafish diras1 Promoted Neurite Outgrowth in Neuro-2a Cells and Maintained Trigeminal Ganglion Neurons In Vivo via Rac1-Dependent Pathway.
abstract: The small GTPase Ras superfamily regulates several neuronal functions including neurite outgrowth and neuron proliferation. In this study, zebrafish diras1a and diras1b were identified and were found to be mainly expressed in the central nervous system and dorsal neuron ganglion. Overexpression of green fluorescent protein (GFP)-diras1a or GFP-diras1b triggered neurite outgrowth of Neuro-2a cells. The wild types, but not the C terminus truncated forms, of diras1a and diras1b elevated the protein level of Ras-related C3 botulinum toxin substrate 1 (Rac1) and downregulated Ras homologous member A (RhoA) expression. Glutathione S-transferase (GST) pull-down assay also revealed that diras1a and diras1b enhanced Rac1 activity. Interfering with Rac1, Pak1, or cyclin-dependent kinase 5 (CDK5) activity or with the Arp2/3 inhibitor prevented diras1a and diras1b from mediating the neurite outgrowth effects. In the zebrafish model, knockdown of diras1a and/or diras1b by morpholino antisense oligonucleotides not only reduced axon guidance but also caused the loss of trigeminal ganglion without affecting the precursor markers, such as ngn1 and neuroD. Co-injection with messenger RNA (mRNA) derived from mouse diras1 or constitutively active human Rac1 restored the population of trigeminal ganglion. In conclusion, we provided preliminary evidence that diras1 is involved in neurite outgrowth and maintains the number of trigeminal ganglions through the Rac1-dependent pathway.
authors.affiliation: Institute of Biochemistry, Microbiology and Immunology, Chung Shan Medical University, No. 110, Sec.1, Jianguo N. Rd., Taichung, 40201, Taiwan.
authors.forename: Chi-Wei
authors.initials: CW
authors.lastname: Yeh
authors.affiliation: Institute of Biochemistry, Microbiology and Immunology, Chung Shan Medical University, No. 110, Sec.1, Jianguo N. Rd., Taichung, 40201, Taiwan. lshsu405@yahoo.com.tw.|Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, 40201, Taiwan. lshsu405@yahoo.com.tw.
authors.forename: Li-Sung
authors.initials: LS
authors.lastname: Hsu
mesh_terms: D000107:Acetylation; D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D055785:Gene Knockdown Techniques; D051379:Mice; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D055495:Neurogenesis; D000071446:Neuronal Outgrowth; D009474:Neurons / Q000378:metabolism*; D015398:Signal Transduction; D012668:Trigeminal Ganglion / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000378:metabolism; D015027:Zebrafish / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000378:metabolism*; D054462:p21-Activated Kinases / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
chemical_list: D051376:Actin-Related Protein 2-3 Complex; C000625721:Diras1a protein, zebrafish; C000625722:Diras1b protein, zebrafish; D009419:Nerve Tissue Proteins; D014404:Tubulin; D051300:Wiskott-Aldrich Syndrome Protein Family; D029961:Zebrafish Proteins; D054462:p21-Activated Kinases; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein
keywords: Diras1; Neurite outgrowth; Rac1; Trigeminal ganglion; Zebrafish