Disease relevance of HEXIM2

• We observed proteinase activity in wild-type virus but not in the ts-1 virus, which contains a mutation in the Ad2 L3 endoprotease gene that confers temperature-sensitive processing of virion precursor proteins [1].
• A new method for the in vitro generation of granulomas was developed and characterized in which L3 larvae of Nippostrongylus brasiliensis, as a target for the cellular response, were co-incubated with human mononuclear blood cells [2].
• An Escherichia coli L3 mutant strain is resistant to tiamulin and pleuromutilin, but not valnemulin, implying that valnemulin is better able to withstand an altered rRNA binding surface around the mutilin core [3].
• Protective immunity to the parasitic nematode Onchocerca volvulus (Ov) appears to be directed against molecules of invading L3 larvae [4].

High impact information on HEXIM2

• Despite their similar functions, HEXIM1 and HEXIM2 exhibit distinct expression patterns in various human tissues and established cell lines [5].
• Here we show that, like HEXIM1, a highly homologous protein named HEXIM2 also possesses the ability to inactivate P-TEFb to suppress transcription through a 7SK-mediated interaction with P-TEFb [5].
• Compensatory contributions of HEXIM1 and HEXIM2 in maintaining the balance of active and inactive positive transcription elongation factor b complexes for control of transcription [5].
• HEXIM2 is expressed in HeLa and Jurkat cells, and glycerol gradient analysis and immunoprecipitations indicate that HEXIM2, like HEXIM1, has a regulated association with P-TEFb [6].
• Positive transcription elongation factor b (P-TEFb) regulates eukaryotic gene expression at the level of elongation, and is itself controlled by the reversible association of 7SK RNA and an RNA-binding protein, HEXIM1 or HEXIM2 [7].

Biological context of HEXIM2

• RESULTS: Here we report that Tat transactivation is effectively inhibited by co-expression of HEXIM1 or its paralog HEXIM2 [8].
• The L3-cDNA clone was identified by hybrid-selected translation analysis and contains the complete 3' noncoding region and an open reading frame of 432 nucleotides [9].
• A recombinant antigen (Ll-SXP-1), preferentially recognized by serum samples from experimentally infected rhesus monkeys, was identified from a Loa loa L3 cDNA library [10].
• Using TdT-mediated dUTP-biotin nick end labeling for flow cytometry, CD4(+) lymphocytes from Mf-infected mice cultured with Ag showed high levels of apoptosis when compared to those from L3-infected mice which proliferated well in response to Ag [11].
• However, homologous sequences to ES62 have recently been found in L1 and L3 cDNA libraries of certain human filarial nematodes [12].

Anatomical context of HEXIM2

• METHODS: Nine animals underwent a left-sided hemisection of the spinal cord at T-12 via left-sided T9-L3 hemilaminectomy, with section of all ipsilateral lumbrosacral ventral nerve roots [13].
• In the experimental group (five animals), an NAG obtained from the right peroneal nerve was anastomosed with the sectioned and electrophysiologically selected lumbar ventral roots (left L-3 and L-4) controlling the left quadriceps muscle and then implanted into the left ventrolateral T-10 cord [13].
• YmL9, a nucleus-encoded mitochondrial ribosomal protein of yeast, is homologous to L3 ribosomal proteins from all natural kingdoms and photosynthetic organelles [14].

Associations of HEXIM2 with chemical compounds

• The following PAHs have been employed: acenaphthylene C12H8 (L1); acenaphthene C12H10 (L2); anthracene (L3) and phenanthrene (L4), C14H10; pyrene (L5) and fluoranthene (L6), C16H10; a series of isomers of the C18H12 composition: 1,2-benzanthracene (L7), triphenylene (L8), and chrysene (L9) [15].
• From these values and the O2 binding curve of tri-aquomet HbXL, L3 was calculated to be 2.7 for the tri-aquomet derivative [16].
• L3 binds two Cu(II) ions with two pendant groups in tridentate chelate modes and, with the incorporation of phosphate esters, various dinuclear units are formed in 3 and 4 [17].
• The hydrolytic activity of 2 and a dicopper(II) complex of L3 was examined with tris(p-nitrophenyl) phosphate (TNP) as a substrate [17].
• The addition of these metal ions to dichloromethane solutions of L1, L2, and L3 produce strong changes in the absorption and emission spectra of these ligands [18].

Physical interactions of HEXIM2

• Its activity is inhibited by association with the HEXIM1 or HEXIM2 protein bound to 7SK small nuclear RNA [19].

Analytical, diagnostic and therapeutic context of HEXIM2

• Electrophoretic mobility shift assays and in vitro kinase assays demonstrate that HEXIM2 forms complexes containing 7SK and P-TEFb and, in conjunction with 7SK, inhibits P-TEFb kinase activity [6].
• A sequence analysis of these cDNAs and cross-reactivity of the 94-kD-specific antibodies to the soybean lipoxygenase (LOX) L-1, L-2, and L-3 proteins and soybean LOX L-1-specific antibodies to the 94-kD protein identified it as a member of the LOX gene family [20].
• Mammalian reoviruses were detected and identified by a combined cell culture-reverse transcription-PCR (RT-PCR) assay with novel primers targeting the L3 gene that encodes the lambda3 major core protein [21].
• In this study, the cellular immune reaction to such an Ov L3 protein (S1) which is protective in an animal model was analyzed using peripheral blood mononuclear cells (PBMC) of individuals from a hyperendemic area in West Africa who were exposed to Ov but remained free from disease ('putatively immune individuals') [4].
• However, examination by PCR of the mRNA for ES62 revealed that it was found in the L1 and L3 larvae [12].

References