Patent ID: 7195869

Claim:
A method for searching for a gene coding for a protein which is transported from cytoplasm into a nucleus through a nuclear pore in a eukaryotic cell, comprising the steps of: (a) introducing a library of genes coding for fusion proteins of a marker protein whose localization in a cell can be detected and a part or whole of a search object protein into eukaryotic cells to allow expression of the genes in the transgenic cells so that the fusion proteins are produced, wherein one or more genes coding for a fusion protein autonomously transporting into the nucleus with no stimulus are eliminated from the library beforehand; (b) dividing the transgenic cells into two groups and stimulating only cells of one group, wherein the stimulation transports a nuclear transport protein into nuclei of the cells, thereby transporting the fusion protein comprising a nuclear transport protein into nuclei of the cells; (c) detecting localization of the fusion proteins in the cells by using the marker protein in each of the stimulated cell group and the unstimulated cell group and isolating cells in which the fusion proteins are localized in the nuclei or their nuclei; and (d) recovering genes coding for a fusion protein from the isolated cells or their nuclei, and comparing genes recovered from the stimulated cell group and genes recovered from the unstimulated cell group.