Protein kinase N1, a cell inhibitor of Akt kinase, has a central role in quality control of germinal center formation.

Germinal centers (GCs) are specialized microenvironments in secondary lymphoid organs where high-affinity antibody-producing B cells are selected based on B-cell antigen receptor (BCR) signal strength. BCR signaling required for normal GC selection is uncertain. We have found that protein kinase N1 (PKN1, also known as PRK1) negatively regulates Akt kinase downstream of the BCR and that this regulation is necessary for normal GC development.