The function and expression of sproutin, a novel neurite outgrowth factor

TA20 cDNA was previously cloned as a neurite outgrowth factor from a hybrid oma of mouse and rat cells, NG108-15. To clarify the detailed function and tissue distribution of this gene, homologous sequences of rat and mouse wer e identified. The cloned sequences had no homology with known genes, and wa s designated as sproutin. A predicted open reading frame of rat sproutin wa s transfected into human SK-N-SH cells. The over-expressed protein was dist ributed in cytoplasm and neurites, and caused an increase in the levels of microtuble associated proteins, but not that of phosphorylated neurofilamen t-H. The percentage of cells with neurites, the length of neurites and the number of neurites per cell were increased by sproutin transfection. Sprout in mRNA was brain specific. These results suggest that an increase in sprou tin promotes dendritic extension. NeuroReport 10:2089-2094 (C) 1999 Lippinc ott Williams & Wilkins.