Expression of the Orphan Protein Plet-1 During Trichilemmal Differentiation of Anagen Hair Follicles

The study investigated the expression and function of the orphan protein Plet-1 during trichilemmal differentiation in anagen hair follicles. Plet-1, identified by the 33A10 monoclonal antibody, was highly expressed in differentiated outer root sheath (ORS) cells and the companion layer (CL). It was found to be a glycosylated, GPI-anchored protein involved in terminal differentiation of keratinocytes. Knockdown experiments showed that reducing Plet-1 levels decreased cell motility but increased adhesion to collagens I and IV. Plet-1 was also observed at the leading edge of wounds, suggesting a role in keratinocyte adhesion and motility during wound healing. The findings indicated that Plet-1 is crucial for the structural and functional development of hair follicles during the anagen phase.