UBL4A is a component of the BAT3 complex, which is a multiprotein complex involved in the post-translational delivery of tail-anchored （TA） membrane proteins to the endoplasmic reticulum membrane. Post-translational modification by ubiquitin and ubiquitin-related proteins plays decisive roles in protein degradation and in regulation of crucial cellular processes. Due to the fact that in mammals, transcription halts during late spermiogenesis as a result of compaction of the spermatid genome, which creates a special need for robust post-transcriptional regulation.
