Researchers at Nagoya University have uncovered a surprising ability in a well-known brain enzyme: it builds a sugar chain called polysialic acid on itself, becomes secreted from the cell, and then reactivates outside once the chain is removed. The finding, published in the Journal of Biological Chemistry, overturns a long-held assumption about how this critical sugar chain is produced.
This discovery rewrites the understanding of polysialic acid's role in brain development and function. The sugar chain is essential for neural plasticity and cell migration, processes linked to learning and memory. The enzyme's self-regulation suggests a more dynamic control mechanism than previously thought.
The enzyme's behavior is unprecedented: it deactivates within the cell, exits, and then switches back on externally after shedding the sugar chain. This represents a novel way an enzyme can regulate its own activity, according to the researchers. The study emerged from a chance observation during routine experiments.
The implications extend beyond basic neuroscience. If this mechanism is common, it could reshape how scientists approach enzyme regulation in other contexts. Future work will explore whether similar self-modifying processes occur in other enzymes, potentially opening new therapeutic avenues for neurological conditions.
The finding was led by Nagoya University scientists and published in the Journal of Biological Chemistry. Further research is needed to confirm whether this behavior is unique or widespread among enzymes.