  We compute the anomaly of the axial U(1) current in the A-model on a
Calabi-Yau manifold, in the presence of coisotropic branes discovered by
Kapustin and Orlov. Our results relate the anomaly-free condition to a recently
proposed definition of graded coisotropic branes in Calabi-Yau manifolds. More
specifically, we find that a coisotropic brane is anomaly-free if and only if
it is gradable. We also comment on a different grading for coisotropic
submanifolds introduced recently by Oh.
