The P124A mutation of SRP14 alters its migration on SDS-PAGE without impacting its function

• The P124A mutation in SRP14 causes faster migration on SDS-PAGE, explaining observed variations across cell lines. • Mutations within the alanine-rich domain (P117A, A121P) affect migration, while those outside do not. • SRP14P124A retains functional equivalence to wild-type SRP14 in RNA stability, cell morphology, and growth. • This natural variant highlights the importance of proline residues in protein electrophoretic behavior without compromising function.