Significance The localization of proteins within the cell is assumed to be important for their function. However, we have limited understanding of protein relocalization in response to genetic changes or drug treatments and almost no understanding of the effects of protein relocation on cellular homeostasis. To address this, we have developed a method to systematically create protein fusions between a query protein and most other proteins in the cell. As proof of principle, we relocalized proteins to the kinetochore, a large protein complex essential for chromosome segregation and cell division. We identify a number of proteins that inhibit cell division via the kinetochore. One such interaction establishes a critical role for specific phosphorylation in kinetochore function.