An in vitro study found that human tau protein suppresses DNA replication . It was demonstrated that tau binding to the template results in inhibition . The ribosomal DNA locus is where Tau and other upstream binding factors are recruited . Upon tau downregulation, a new subclass of ultrafine anaphase bridges forms in human ribosomes, which is caused by a decrease in ribonucleotide levels, ribosomal RNA synthesis, and recruitment of upstream binding factors . In Alzheimer's disease, pathogenic Tau is linked to the cytoplasmic mislocalization of the RNA polymerase II subunit RPB1 . Before Tau phosphorylation and neurofibrillary tangles form in Alzheimer's disease, neuronal RNA levels are decreased and RNA polymerase II is hyperphosphorylated .