The function of TMUB1 (transmembrane and ubiquitin like domain containing 1, Ensembl gene identifier ENSG00000164897) is as follows. Involved in sterol-regulated ubiquitination and degradation of HMG-CoA reductase HMGCR (PubMed:21343306). Involved in positive regulation of AMPA-selective glutamate receptor GRIA2 recycling to the cell surface (By similarity). Acts as a negative regulator of hepatocyte growth during regeneration (By similarity). {ECO:0000250|UniProtKB:Q53AQ4, ECO:0000250|UniProtKB:Q9JMG3, ECO:0000269|PubMed:21343306}. [iHOPS]: May contribute to the regulation of translation during cell-cycle progression. May contribute to the regulation of cell proliferation (By similarity). May be involved in centrosome assembly. Modulates stabilization and nucleolar localization of tumor suppressor CDKN2A and enhances association between CDKN2A and NPM1 (By similarity). .