Ribosomal 60S subunit protein L12A functions as a ribophagy receptor; phosphorylation by Atg12 triggers ribophagy during starvation; rpl12a rpl12b double mutant exhibits slow growth and slow translation; homologous to human RPL12, Drosophila rpl12, and C. elegans ppl-12 that all function as conserved ribophagy receptors; RPL12A has a paralog, RPL12B, that arose from the whole genome duplication