User:Brian Boyle/Sandbox 1: Difference between revisions

'''Peregrin''', also known as Bromodomain and PHD Finger-containing 1 ('''BRPF1''') is a 137 kDa protein that plays a versatile role in epigenetic signaling events. It contains three chromatin reader domains, including a <scene name='91/910741/Apo_bromodomain/1'>bromodomain</scene>, <scene name='91/910741/Apo_pzp/1'>PZP domain</scene> (two PDH fingers separated by a Zinc Knuckle), and '''proline-tryptophan-tryptophan-proline (<scene name='91/910741/Pwwp_unliganded/1'>PWWP</scene>) domain''' (from N to C terminus)<ref name="Yan">PMID:27939640</ref>. Through these three domains, it is capable of recognizing both modified and unmodified histones, as well as non-specifically binding DNA <ref name="Klein">PMID:31711755</ref>,<ref name="Glass1">PMID:24333487</ref>. BRPF1 carries out its function as a component of the MOZ (monocytic leukemic zinc-finger protein) histone acetyltransferase (HAT) complex <ref name="Obi">PMID:33554132</ref>. This complex is involved in the regulation of gene expression, particularly those involved with skeletal development and hematopoiesis <ref>PMID:19254709</ref>,<ref>PMID:27500495</ref>.

The BRPF1 bromodomain has been shown to recognize and bind to various acetylated lysine marks on the N-terminal tails of histones tails <ref name="Glass1" />. Using isothermal titration calorimetry (ITC) experiments, it was found that the BRPF1 bromodomain preferentially binds to histone H4 acetylated at positions K5 ([[2rs9]]) and K12 ([[4qyd]]) as well as H2A at position K5 ([[4qyl]]) <ref name="Obi" />,<ref name="Glass1" />. Interestingly, the BRPF1 bromodomain has also been shown to bind di-acetylated histone peptides with high affinity, including H4K5acK8ac and H4K5acK12ac <ref name="Obi" />. Acetyllysine recognition is coordinated by a number of residues in the bromodomain's binding pocket. Using NMR chemical shift perturbation experiments, Glass et al. reported several <scene name='91/910741/Nmr_resi_h4_binding/1'>key residues</scene> the undergo conformational changes upon histone H4 ligand binding (I27, L34, E36, V37, N83, and I88)<ref name="Obi" />. Notably, asparagine 83 was among these. The interaction between the amide nitrogen of asparagine with the carbonyl of the acetyllysine group is conserved in all bromodomains and is necessary for binding to occur <ref name ="Obi" />,<ref name ="Lubula_2014" />.   

The MOZ Histone Acetyltransferase Complex is a tetramer consisting of MEAF6, ING5, BRPF1 (or BRPF2/BRPF3) and MOZ (or MORF)<ref name="Klein" />. Within BRPF1, there are two non-chromatin-binding modules surrounding the PZP domain that are responsible for its association with the MOZ HAT Complex. On the N-terminal side of the PZP, lies the MOZ/MORF binding domain<ref name="Lalonde">PMID:24065767</ref>. On the other side of the PZP domain, there is a small module involved in binding to ING5 and MEAF6<ref name="Ullah">PMID:18794358</ref>. BRPF1 seems to be required for the formation of the MOZ HAT complex, as it acts as a bridge associating MOZ or MORF with ING5 and MEAF6<ref name ="Ullah" />.