Acts as a negative regulator of autophagy, through promoting ubiquitination and degradation of LRSAM1, an E3 ubiquitin ligase that promotes autophagy in response to starvation or infecting bacteria. Interacts with LRSAM1. Mainly present in the nucleus and part in the cytoplasm. The PHD-type zinc-finger domain is required for interaction with LRSAM1 and negative regulation of autophagy. Belongs to the PHF23 family.