MeR-PIWIL4:2'-O-methyl-piRNA:TDRD9:MAEL:TDRKH dissociates and MeR-PIWIL4:2'-O-methylpiRNA, TDRD9, MAEL translocate from cytosol to nucleus in an unknown association and order of events

As inferred from homologs in mouse, PIWIL4 is loaded with piRNA in the cytosol and then translocates to the nucleus where it directs transcriptional silencing of cognate loci by an unknown mechanism. Most cellular PIWIL4 is translocated to the nucleus at E16.5 of mouse development and proper localization depends on PIWIL2 and TDRD1. TDRD9 and MAEL interact with PIWIL4, are observed in the nucleus, and may play a role in the translocation of PIWIL4. Knockout of TDRD9, however, does not affect nuclear localization of PIWIL4. Knockout of MAEL delays but does not prevent localization of PIWI4L to the nucleus. TDRKH is required for translocation of PIWIL4, however TDRKH is only observed in the cytosol.

据对小鼠同源蛋白的研究推断，PIWIL4在细胞质中装载piRNA后，随后转移至细胞核，并在其中通过一种未知的机制指导同源位点的转录沉默。在鼠类发育的E16.5阶段，大多数细胞中的PIWIL4都会转移到细胞核，其正确的定位依赖于PIWIL2和TDRD1。TDRD9与MAEL相互作用，并在细胞核中被观察到，可能参与PIWIL4的转移。然而，TDRD9的敲除并不影响PIWIL4的核定位。MAEL的敲除会延迟但不会阻止PIWI4L向细胞核的转移。TDRKH对于PIWIL4的转移是必需的，但TDRKH仅在细胞质中被观察到。