Nach Is a Novel Subgroup at an Early Evolutionary Stage of the CNC-bZIP Subfamily Transcription Factors from the Marine Bacteria to Humans

Normal growth and development, as well as adaptive responses to various intracellular and environmental stresses, are tightly controlled by transcriptional networks. The evolutionarily conserved genomic sequences across species highlights the architecture of such certain regulatory elements. Among them, one of the most conserved transcription factors is the basic-region leucine zipper (bZIP) family. Herein, we have performed phylogenetic analysis of these bZIP proteins and found, to our surprise, that there exist a few homologous proteins of the family members Jun, Fos, ATF2, BATF, C/EBP and CNC (cap’n’collar) in either viruses or bacteria, albeit expansion and diversification of this bZIP superfamily have occurred in vertebrates from metazoan. Interestingly, a specific group of bZIP proteins is identified, designated Nach (Nrf and CNC homology), because of their strong conservation with all the known CNC and NF-E2 p45 subunit-related factors Nrf1 and Nrf2. Further experimental evidence has also been provided, revealing that Nach1 and Nach2 from the marine bacteria exert distinctive functions, when compared with human Nrf1 and Nrf2, in the transcriptional regulation of antioxidant response element (ARE)-battery genes. Collectively, further insights into these Nach/CNC-bZIP subfamily transcription factors provide a novel better understanding of distinct biological functions of these factors expressed in distinct species from the marine bacteria to humans.


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from Gallid herpesvirus 2, bacterial Nach1/2 with human Nrf1γ. The symbols * and # represent the "a" 16 and "d" positions in heptad repeats of LZ region, respectively. (g) Shows an additional alignment of 17 the full length Nach1/2 proteins with human NF-E2 P45.

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Those distinct characteristics of BRLZ domain were analyzed by using three different softwares 20 DNAMAN8.0, MEME and Web-logo with default parameters. 21 22 Figure S3. Alignment of the CNC domains from those identified Nach/CNC-bZIP subfamily 23 proteins. The blue and red asterisks represent not gregarious bZIPs in zebrafish and some CNC 24 members with high homology beyond vertebrates, respectively. The light blue and pink 25 backgrounds are 50% to 75% and 75% to 100% homology level. Figure S4. Alignment of the BRLZ domains from those identified Nach/CNC-bZIP subfamily 28 proteins. The blue and red asterisks represent not gregarious bZIPs in zebrafish and some CNC 29 members with high homology beyond vertebrates, respectively. The black symbols * and # represent 30 the "a" and "d" positions in heptad repeats of LZ region, respectively. The light blue, pink and black 31 backgrounds are 50% to 75%, 75% to 100% and 100% homology level.

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The left red asterisks represent unnamed bZIPs. The black symbols * and # represent the "a" and "d" 53 positions in heptad repeats of LZ region, respectively. The light blue, pink and black backgrounds 54 are 50% to 75%, 75% to 100% and 100% homology level.

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The left blue and red asterisks represent interesting bZIPs and unnamed bZIPs, respectively. The 64 different colors above symbols * and # represent the "a" and "d" positions in heptad repeats of LZ 65 region, respectively. The red triangles represent the amino acids in Gh2-MEQ is different from 66 others. The light blue, pink and black backgrounds are 50% to 75%, 75% to 100% and 100% homology 67 level. Figure S11. Alignment of the BRLZ domains from within both PAR (a) and E4BP4 (b) subfamilies.

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The left blue, green and red asterisks represent not gregarious, contained two BRLZ domains and 71 unnamed bZIPs, respectively. The different colors above symbols * and # represent the "a" and "d" and black backgrounds are 50% to 75%, 75% to 100% and 100% homology level. Figure S12. Alignment of the BRLZ domains from within the C/EBP subfamilies. The left blue and 77 red and black asterisks represent interesting, unnamed and representative bZIPs, respectively. The 78 different colors above symbols * and # represent the "a" and "d" positions in heptad repeats of LZ 79 region, respectively. The grey boxes represent highly similar bZIPs, the red triangle represents a 80 cumbrous leucine in Dr-CHOP. The light blue, pink and black backgrounds are 50% to 75%, 75% to 81 100% and 100% homology level. Figure S13. Alignment of the BRLZ domains from within both CREB (a) and XBP1 (b) subfamilies.

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The left blue, red and black asterisks represent interesting, unnamed and representative bZIPs, 85 respectively. The different colors above symbols * and # represent the "a" and "d" positions in 86 heptad repeats of LZ region, respectively. The light blue, pink and black backgrounds are 50% to 87 75%, 75% to 100% and 100% homology level.