Histone H2A-B variant type 1 (H2A.B)

Histone H2A-B variant type 1 (H2A.B, formerly known as H2A.Bbd or H2AB1) is an atypical replication-independent histone H2A variant found in mammals that incorporates into nucleosomes, altering chromatin structure and dynamics[1][3][5]. Unlike canonical H2A, H2A.B is shorter, rapidly exchanges within chromatin, and is predominantly associated with actively transcribed genes, DNA replication, and DNA repair regions[2][3][5]. It plays a key role in transcriptional regulation, being linked with RNA polymerase elongation and pre-mRNA splicing, and is essential for mRNA processing efficiency[5][6]. H2A.B is also involved in the upregulation of ribosome biogenesis, especially in certain cancers[4][6], and is considered a cancer/testis factor with high expression in some tumor types, notably Hodgkin lymphoma[4][6]. There are no approved drugs directly targeting H2A.B, and it is not considered a classical pharmacological target such as a receptor or enzyme[5][7].

Other names

Histone H2A-Bbd type 1H2AB1H2AFB1H2A.BbdH2A.B.2H2A Barr body-deficientH2A.Lap1H2A histone family member B1H2A.B.3

Not a direct pharmacological target; no direct drug mechanisms.