MCM3AP
MCM3AP, also known as GANP, SAC3, Map80 and KIAA0572, is a nuclear protein that binds and acetylates the replication factor MCM3. It contributes to the control of DNA replication initiation and to antibody gene diversification in germinal centres. Browse Assay Genie's current range of MCM3AP research reagents below, or read on for the biology behind the target.
MCM3AP is an acetyltransferase that binds to and acetylates MCM3, one of the MCM proteins essential for the initiation of DNA replication. Through this activity it plays a role in starting replication and participates in the controls that ensure DNA replication initiates only once per cell cycle. Because mutagenesis of the MCM3 nuclear localisation signal affects binding to this protein, MCM3AP may also help MCM3 reach the nucleus.
The protein also acts on chromatin in B cells. By acetylating histones, it affects nucleosome assembly at immunoglobulin variable region genes and promotes recruitment and positioning of the transcription complex. This favours targeting by the DNA cytosine deaminase AICDA (AID) and so promotes somatic hypermutation. The name germinal-centre associated nuclear protein (GANP) reflects this setting: DNA-primase activity that depends on phosphorylation was reported to be up-regulated in germinal centres induced by antigen immunisation.
MCM3AP is a member of the SAC3 family. HGNC places the gene in the lysine acetyltransferases group and in the transcription and export complex 2 group. UniProt records localisation at the nuclear envelope, nuclear pore complex and nucleoplasm, as well as chromosome and cytoplasm. The gene is expressed in brain or neuronal tissue, and an allelic variant encoding lysine instead of the conserved glutamate at position 915 has been identified in patients with mild intellectual disability. The mouse ortholog is Mcm3ap. Earlier names described it as an MCM3-associated protein, hence the symbol.
MCM3AP acetylates MCM3 and helps ensure that DNA replication initiates only once per cell cycle, making it relevant to replication control studies.
By acetylating histones at immunoglobulin variable region genes, it promotes AICDA targeting and somatic hypermutation in germinal-centre biology.
As a lysine acetyltransferase (EC 2.3.1.48), it links histone acetylation to nucleosome assembly and transcription complex positioning.
A Glu915Lys variant has been found in patients with mild intellectual disability, and the gene is expressed in brain and neuronal tissue.
MCM3AP binds and acetylates MCM3, contributing to the initiation of DNA replication and to the controls that limit replication to once per cell cycle. It also acetylates histones at immunoglobulin variable region genes, which favours AICDA targeting and promotes somatic hypermutation.
The official name describes it as an MCM3-associated protein. UniProt calls it germinal-centre associated nuclear protein (GANP). Other aliases are Map80, KIAA0572 and SAC3, the last reflecting its membership of the SAC3 family. Earlier HGNC names referred to the S. cerevisiae minichromosome maintenance deficient 3 nomenclature.
An allelic variant encoding lysine at position 915 instead of the conserved glutamate has been identified in patients with mild intellectual disability. The gene is expressed in brain or neuronal tissue. A mouse ortholog, Mcm3ap, exists; check the datasheet of any product for its validated reactivity.
MCM3, the other MCM replication complex components and related proteins in DNA replication initiation.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O60318; product specifications from Assay Genie datasheets.