5-Hydroxytryptamine Receptor 5B (HTR5B)

Many symptoms induced by isolation rearing of rodents may be relevant to neuropsychiatric disorders, including depression. The transcription factor ATF-7 is structurally related to ATF-2, which is activated by various stresses, including inflammatory cytokines. Atf-7-deficient mice exhibit abnormal behaviours and increased 5-HT receptor 5B (Htr5b) mRNA levels in the dorsal raphe nuclei. ATF-7 silences the transcription of Htr5B by directly binding to its 5'-regulatory region, and mediates histone H3-K9 trimethylation via interaction with the ESET histone methyltransferase. Isolation-reared wild-type (WT) mice exhibit abnormal behaviours that resemble those of Atf-7-deficient mice. Upon social isolation stress, ATF-7 in the dorsal raphe nucleus is phosphorylated via p38 and is released from the Htr5b promoter, leading to the upregulation of Htr5b.