Platelets achieve bleeding arrest at sites of vascular injury via secretion of secretory proteins
from their storage granules, termed α-granules. We have recently analyzed granule
targeting of platelet factor 4 (PF4), a secretory α-granule chemokine, and demonstrated that
PF4 α-granule storage relied upon determinants within PF4 mature sequence. To define
these determinants, PF4 mutants fused to the fluorescent reporter protein green fluorescent
protein were generated by progressive deletions and site-directed mutagenesis. They were …