This is the C-terminal domain found in NF-kappa-B-activating protein (Nkap) and a hypothetical open reading frame on chromosome 6, c6orf194. Functional studies in Nkap indicate that this domain is the HDAC3 binding domain and is required for transcriptional repression [1]. Nkap functions as a transcriptional repressor on Notch target genes, and is required for T cell development and acquisition of functional competency [1, 2, 3].

1: NKAP is a transcriptional repressor of notch signaling and is required for T cell development. Pajerowski AG, Nguyen C, Aghajanian H, Shapiro MJ, Shapiro VS; Immunity. 2009;30:696-707. PMID:19409814

2: NKAP is required for T cell maturation and acquisition of functional competency. Hsu FC, Pajerowski AG, Nelson-Holte M, Sundsbak R, Shapiro VS; J Exp Med. 2011;208:1291-1304. PMID:21624937

3: The transcriptional repressor NKAP is required for the development of iNKT cells. Thapa P, Das J, McWilliams D, Shapiro M, Sundsbak R, Nelson-Holte M, Tangen S, Anderson J, Desiderio S, Hiebert S, Sant'angelo DB, Shapiro VS; Nat Commun. 2013;4:1582. PMID:23481390