High impact information on MENT-1

• Ectopic MENT expression in NIH 3T3 cells caused a large-scale and specific remodeling of chromatin marked by H3me2K9 [1].
• We observed two sharp transitions of MENT concentration coinciding with the beta-globin boundary elements [1].
• The MENT distribution profile was opposite to that of acetylated core histones but correlated with that of histone H3 dimethylated at lysine 9 (H3me2K9) [1].
• Mutational analysis of MENT and experiments with deacetylase inhibitors revealed the essential role of the reaction center loop domain and an inhibitory affect of histone hyperacetylation on the MENT-induced chromatin remodeling in vivo [1].
• Cryoelectron microscopy of chicken granulocyte chromatin, which is highly enriched with MENT, reveals exceptionally compact polynucleosomes, which maintain a level of higher order folding above that imposed by linker histones [2].

Biological context of MENT-1

• We show that MENT is immunolocalized in granulocyte heterochromatin, where it is one of the most abundant chromatin proteins ( approximately 2 molecules/200 base pairs of DNA) [3].
• The amino acid sequence of MENT reveals a close structural relationship with serpins, a large family of proteins known for their ability to undergo dramatic conformational transitions [2].
• A novel nonhistone protein (MENT) promotes nuclear collapse at the terminal stage of avian erythropoiesis [4].

Anatomical context of MENT-1

• One of them (42 kDa) is identified as MENT, a protein previously shown to be associated with repressed chromatin from mature chicken erythrocytes [3].
• Chromatin structure in granulocytes. A link between tight compaction and accumulation of a heterochromatin-associated protein (MENT) [3].
• MENT ectopically expressed in a mammalian cell line is transported into nuclei and is associated with intranuclear foci of condensed chromatin [2].
• In vertebrate blood cells, these changes can be traced to the accumulation of a developmentally regulated heterochromatin protein, MENT [2].
• One of the positively charged domains bears a significant similarity to the chromatin binding region of nuclear lamina proteins and with the A.T-rich DNA-binding motif, which may account for the targeting of MENT to peripheral heterochromatin [2].

Associations of MENT-1 with chemical compounds

• MENT is the first nuclear protein structurally related to the serine protease inhibitor family [3].

Analytical, diagnostic and therapeutic context of MENT-1

• In intact erythrocytes, MENT immunofluorescence was found in foci close to the nuclear periphery, while in isolated, decondensed nuclei, the fluorescence signal was uniformly distributed [5].

References