Catalyzes the reduction of 1-pyrroline-5-carboxylate (PCA) to L-proline. L-proline + NADP(+) = 1-pyrroline-5-carboxylate + 2 H(+) + NADPH L-proline + NAD(+) = 1-pyrroline-5-carboxylate + 2 H(+) + NADH Amino-acid biosynthesis; L-proline biosynthesis; L-proline from L-glutamate 5-semialdehyde: step 1/1. Belongs to the pyrroline-5-carboxylate reductase family.