Aged hematopoietic stem cells (HSCs) exhibit compromised reconstitution capacity. While, the molecular mechanisms behind this phenomenon are not fully understood. In this study, we observed that the expression of FUS is increased in aged HSCs and enforced FUS recapitulates the phenotype of aged HSCs through RGG-mediated aberrant FUS phase transition. By utilizing Fus-gfp mice, we observed that FUShigh HSCs exhibit compromised FUS mobility and resemble aged HSCs both functionally …