Identifiers and Description

Gene Model Identifier

TTHERM_00823720

Standard Name

HHO1 (Histone H One )

Aliases

PreTt20442 | 141.m00099 | 3682.m00033

Description

HHO1 Tonsoku-like protein; Histone H1; macronuclear linker histone that associates with inter-nucleosomal DNA; lacks globular domain typical of linker histones; five phosphorylation; hypothetical protein

Genome Browser (Macronucleus)

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Genome Browser (Micronucleus)

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External Links

Gene Ontology Annotations

Cellular Component

Biological Process

Domains

No Data fetched for Domains

Gene Expression Profile

Vegetative Cell Cycle (Zhang et al., 2023)

GeneMania

Tetrahymena Stock Center

  • ( SD01744 ) Macronucleus: GFP tagged HHO1
  • ( SD02216 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid (charge patch) and 5 other sites to lysine
  • ( SD02217 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid (charge patch) and 5 other sites to lysine with GFP tag
  • ( SD02218 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to alanine (charge patch) and 5 other sites to glutamine,GFP at c-terminus
  • ( SD02219 )
  • ( SD02220 )
  • ( SD02221 )
  • ( SD02222 )
  • ( SD02223 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to alanines
  • ( SD02224 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to alanines
  • ( SD02294 )
  • ( SD02295 )
  • ( SD02296 )
  • ( SD02299 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid
  • ( SD02300 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid
  • ( SD02301 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid
  • ( SD02476 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid (charge patch) and T60K,I64K, H65K,T67K,T69K
  • ( SD02477 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid (charge patch) and P136K,IA137K, A141K,T145K, A148K
  • ( SD02478 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid (charge patch) and T37K,A44K, T46K,V49K,V53K and GFP tag
  • ( SD02485 ) Macronucleus: HHO1 with E5 charge patch inserted into coding region of MTT1
  • ( SD02504 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to alanine (charge patch) and 5 other sites to glutamine.
  • ( SD02505 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to alanine (charge patch) and 5 other sites to glutamine, c-terminal GFP.
  • ( SD02541 )
  • ( SD02542 )
  • ( SD02543 )
  • ( SD02607 ) Macronucleus: Change Threonine 35,47 and serine 43,45 to glutamic acid
  • ( SD02634 ) Macronucleus: HHO1 coding replaced by blasticidin cassette
  • ( SD02636 )
  • ( SD02637 )
  • ( SD02706 ) Macronucleus: Change Threonine 35, 47; Serines 43,45 to alanines.
  • ( SD02707 ) Macronucleus: Change Threonine 35, 47, and 54 to alanines.
  • ( SD02708 ) Macronucleus: Change Threonine 35 and 54 to alanines.
  • ( SD02775 ) Macronucleus: Change Threonine 35,47,54 and serine 43,45 to glutamic acid
  • ( SD02789 ) Macronucleus: Neo2 into HHO1 locus
  • ( SD02815 ) Macronucleus: Neo2 into HHO1 and MLH1
  • ( SD02816 ) Macronucleus: Neo2 into HHO1 and MLH1

Homologs

No Data fetched for Homologs

General Information

No. Gene Name(s) Paragraph Text
2216 NGOA1, HHO1, CYP1, CDC2 HHO1 knockouts show no global increase or decrease in the amount of transcription in the cell; however, these same knockouts also show that Hho1p is important for the transcriptional regulation of individual genes in response to stimuli, such as starvation. The differential regulation of Hho1p by phosphorylation under vegetative growth and starvation conditions has been well studied. During vegetative growth, Hho1p is phosphorylated on five closely spaced residues, preventing it from interacting with chromatin, likely by interfering with its ability to bind DNA. Under these conditions, expression is increased for CDC2, a homolog of the cyclin dependent kinases responsible for histone H1 phosphorylation, possibly creating a positive feedback loop that promotes the cell cycle. During starvation conditions, Hho1p is dephosphorylated, allowing it to bind to chromatin. This stimulates the expression of some genes, including ngoA, and protease genes such as CYP1, while inhibiting expression of other genes, such as CDC2. This decrease in CDC2 expression may be responsible for cell cycle arrest during starvation.
2215 MLH1, HHO1 The HHO1 gene encodes the macronuclear linker histone H1 protein; the MLH1 gene encodes a polyprotein comprising a set of four micronuclear linker histone proteins (alpha, beta, gamma, and delta) unrelated to Hho1p. Histone H1 and the MLH proteins are chromatin proteins that associate with the inter-nucleosomal (linker) DNA. T. thermophila has two nuclei, one of which is transcriptionally active (the macronucleus) and one that is silent during most of the life cycle (the micronucleus). Furthermore, the macronucleus undergoes amitosis, whereas the micronucleus undergoes typical mitosis. The fact that Hho1p and MLH proteins are found exclusively in the macronucleus and micronucleus, respectively, has led to studies of their function, or lack of function, in transcription regulation, mitosis, and amitosis. Surprisingly, an HHO1 knockout showed this gene to be non-essential; its main observable phenotype was an overall decondensation of macronuclear chromatin. MLH1 knockouts, which are also viable, showed a similar phenotype in the micronucleus.

Associated Literature

  1. Ref:31932604: Nabeel-Shah S, Ashraf K, Saettone A, Garg J, Derynck J, Lambert JP, Pearlman RE, Fillingham J (2020) Nucleus-specific linker histones Hho1 and Mlh1 form distinct protein interactions during growth, starvation and development in Tetrahymena thermophila. Scientific reports 10(1):168
  2. Ref:29882620: Iwamoto M, Mori C, Osakada H, Koujin T, Hiraoka Y, Haraguchi T (2018) Nuclear localization signal targeting to macronucleus and micronucleus in binucleated ciliate Tetrahymena thermophila. Genes to cells : devoted to molecular & cellular mechanisms 23(7):568-579
  3. Ref:11972045: Dou Y, Gorovsky MA (2002) Regulation of transcription by H1 phosphorylation in Tetrahymena is position independent and requires clustered sites. Proceedings of the National Academy of Sciences of the United States of America 99(9):6142-6
  4. Ref:10983971: Dou Y, Gorovsky MA (2000) Phosphorylation of linker histone H1 regulates gene expression in vivo by creating a charge patch. Molecular cell 6(2):225-31
  5. Ref:10329641: Mizzen CA, Dou Y, Liu Y, Cook RG, Gorovsky MA, Allis CD (1999) Identification and mutation of phosphorylation sites in a linker histone. Phosphorylation of macronuclear H1 is not essential for viability in tetrahymena. The Journal of biological chemistry 274(21):14533-6
  6. Ref:10549296: Dou Y, Mizzen CA, Abrams M, Allis CD, Gorovsky MA (1999) Phosphorylation of linker histone H1 regulates gene expression in vivo by mimicking H1 removal. Molecular cell 4(4):641-7
  7. Ref:7606784: Shen X, Yu L, Weir JW, Gorovsky MA (1995) Linker histones are not essential and affect chromatin condensation in vivo. Cell 82(1):47-56

Sequences 

>TTHERM_00823720(coding)
ATGGCTCCCAGAAGTTCAACTTCCAAGTCTGCTACCAGAGAAAAGAAGGACCACAAGAAG
GCTCCCATCAAGAAAGCCATCGCCAAGAAGGATACTAAGCCTACCCCCACCAAGGGCAAG
GCTGCTTCTGCTTCCACCACCCCCGTCAAGAAGGATGTCACCCCCGTCAAGGCTGATACC
AAGAAGAAGATCCACAAAACCAAAACCATGAAGGAAACCGTCAGCGATGCCAAGAAGACC
GTTCACGCTGCTGCTGGTGATAAGAAGCTCTCTAAAAAGAGACCCGCTAAGGAAGCTGCT
AAGAAGGCTATCAACCCTGGTAAGAAGGCTGCTGCTTAACCCAAGAGCACCAAGAAGGAA
GTTAAGAAGGACAATAAGACTGCCAAGAAGGAAACCAAGAAAGATCATAAGCCCGCTAAG
AAGGAAGCTAAGAAGGAAACCAAGCCTGCCAAGAAAGATGCCAAGAAGAGCTCCAAGCCT
GCCAAGAAGAACTGA



>TTHERM_00823720(gene)
GCGCGATATTATAATCTAATATACAAAATTAAATCGTTAAGAAAAAAACAAGAAAAAAAA
ACTAAAAAACAAATAATATAAAATGGCTCCCAGAAGTTCAACTTCCAAGTCTGCTACCAG
AGAAAAGAAGGACCACAAGAAGGCTCCCATCAAGAAAGCCATCGCCAAGAAGGATACTAA
GCCTACCCCCACCAAGGGCAAGGCTGCTTCTGCTTCCACCACCCCCGTCAAGAAGGATGT
CACCCCCGTCAAGGCTGATACCAAGAAGAAGATCCACAAAACCAAAACCATGAAGGAAAC
CGTCAGCGATGCCAAGAAGACCGTTCACGCTGCTGCTGGTGATAAGAAGCTCTCTAAAAA
GAGACCCGCTAAGGAAGCTGCTAAGAAGGCTATCAACCCTGGTAAGAAGGCTGCTGCTTA
ACCCAAGAGCACCAAGAAGGAAGTTAAGAAGGACAATAAGACTGCCAAGAAGGAAACCAA
GAAAGATCATAAGCCCGCTAAGAAGGAAGCTAAGAAGGAAACCAAGCCTGCCAAGAAAGA
TGCCAAGAAGAGCTCCAAGCCTGCCAAGAAGAACTGATTTTTTTGTAGTAAAGAAATTCC
TCAAAATACTCACATTCACAAGAGAAGAGACTTGATATGAGCAAGTGATCAAAAGGCTTT
AAAGGGAGGTAATTAAAAAAATGAATTCTCTTAGGCTGGAAGAAATCAAGTTCTATACAA
TATTTTCTCAAGTGAAATGTAGAGTAGATGTTAATATAAAATATAATAATAAAAGGGTTA
TGAATCATCAAAAATGCACACTCAACGAGTGTAAAAATGTATATATATCTTCTTAATCAT
TAAATATATTGGTATATAATAATCAACTTTTACTACTAACAAGAAGCAGATAAATCCTTT
ATTGACTTAAATTTATTTATGTATATGTTCTGCATACAATGAATGTGTATTCCTTGATGA
TTTGATAGAGTTTATCATTAACAATA



>TTHERM_00823720(protein)
MAPRSSTSKSATREKKDHKKAPIKKAIAKKDTKPTPTKGKAASASTTPVKKDVTPVKADT
KKKIHKTKTMKETVSDAKKTVHAAAGDKKLSKKRPAKEAAKKAINPGKKAAAQPKSTKKE
VKKDNKTAKKETKKDHKPAKKEAKKETKPAKKDAKKSSKPAKKN