該基因編碼一個具有酸性轉錄激活結構域、4個LRRs（富含亮氨酸重復序列）和GTP結合結構域的蛋白質該蛋白位于細胞核內，是Ⅱ類主要組織相容性復合物基因轉錄的正調控因子，被稱為這些基因表達的“主控因子”該蛋白還結合GTP，并利用GTP結合促進自身運輸到細胞核一旦進入細胞核，它就不會與DNA結合，而是利用一種內在的乙酰轉移酶（AT）活性，以一種類似于輔活化劑的方式起作用。該基因突變與裸淋巴細胞綜合征Ⅱ型（也稱為遺傳性mhcⅡ類缺陷或hlaⅡ類缺陷的聯合免疫缺陷）、類風濕關節炎易感性增加、多發性硬化和可能的心肌梗死有關。已經發現了一些編碼不同亞型的轉錄變體。[ RefSeq，2013月11日]
This gene encodes a protein with an acidic transcriptional activation domain, 4 LRRs (leucine-rich repeats) and a GTP binding domain. The protein is located in the nucleus and acts as a positive regulator of class II major histocompatibility complex gene transcription, and is referred to as the "master control factor" for the expression of these genes. The protein also binds GTP and uses GTP binding to facilitate its own transport into the nucleus. Once in the nucleus it does not bind DNA but rather uses an intrinsic acetyltransferase (AT) activity to act in a coactivator-like fashion. Mutations in this gene have been associated with bare lymphocyte syndrome type II (also known as hereditary MHC class II deficiency or HLA class II-deficient combined immunodeficiency), increased susceptibility to rheumatoid arthritis, multiple sclerosis, and possibly myocardial infarction. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2013]