Molecular characterization of heterochromatin proteins 1a and 1b from the silkworm, Bombyx mori

H. Mitsunobu, M. Izumi, H. Mon, T. Tatsuke, Man Lee, Takahiro Kusakabe

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Heterochromatin protein 1s (HP1s) are nonhistone chromosomal proteins that play a direct role in the formation and maintenance of heterochromatin structure. Similarly to Caenorhabditis elegans, silkworms possess holocentric chromosomes, in which diffused kinetochores extend along the length of each chromosome. We have isolated two silkworm HP1 homologues, BmHP1a and BmHP1b. Cytological analysis showed a unique localization of BmHP1s during cell division, in which these proteins first appear to dissociate from the chromosomes, but then return to enclose the chromosomes during metaphase. BmHP1s formed homo- and hetero-dimers and interacted with BmSu(var)3-9, which is a methyltransferase for histone H3 lysine 9 (H3K9). We further showed, using a silkworm cell-based reporter system, that BmHP1b had higher transcriptional repression activity than BmHP1a, whereas BmHP1a interacted more strongly with BmSu(var)3-9 than did BmHP1b. These results suggest that silkworm HP1a and HP1b may play different roles in heterochromatin formation in holocentric silkworm chromosomes.

Original languageEnglish
Pages (from-to)9-20
Number of pages12
JournalInsect Molecular Biology
Volume21
Issue number1
DOIs
Publication statusPublished - Feb 2012

Fingerprint

Bombyx
Heterochromatin
heterochromatin
Bombyx mori
silkworms
Chromosomes
chromosomes
Proteins
proteins
Histone-Lysine N-Methyltransferase
Non Histone Chromosomal Proteins
Kinetochores
kinetochores
Caenorhabditis elegans
methyltransferases
Homo
Metaphase
metaphase
histones
Cell Division

All Science Journal Classification (ASJC) codes

  • Insect Science
  • Molecular Biology
  • Genetics

Cite this

Molecular characterization of heterochromatin proteins 1a and 1b from the silkworm, Bombyx mori. / Mitsunobu, H.; Izumi, M.; Mon, H.; Tatsuke, T.; Lee, Man; Kusakabe, Takahiro.

In: Insect Molecular Biology, Vol. 21, No. 1, 02.2012, p. 9-20.

Research output: Contribution to journalArticle

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