Mi-2 subfamily
The Mi-2 subfamily includes the human CHD3 and CHD4
proteins, commonly known as Mi-2α and Mi-2β
respectively. Mi-2 was isolated as an autoantigen in
the human disease dermatomyositis 1. These two
proteins and their homologues in D melanogaster and
Xenopus have been recognised as core subunits of
NuRD complexes which link DNA methylation to
chromatin remodelling and deacetylation 2. Human CHD3
differs from CHD4 in having an additional C-terminal
domain which directs Mi-2 complexes containing it
for a specific transcriptional repression role
3. Because Mi-2
proteins are widely expressed but have specific
roles, it has been suggested that their function may
be directed by incorporation of different targeting
subunits 2, 4. It has been shown
that the chromodomains in D melanogaster Mi-2 are
required for activity on nucleosome substrates
5.
An additional human member of the Mi-2 subfamily,
CHD5, may have a role in neural development and
neuroblastomas 6, 7 although its
biochemical associations are unknown. The
Arabidopsis subfamily member, PKL (swollen roots of
mutants resemble a pickle), has been studied and
shown to play a role in repressing embryonic genes
during plant development 8.
names associated with subfamily members
CHD3, Mi-2a, Mi2alpha, ZFH, PKL, pickle, CHD4, Mi-2b,
Mi2beta, let-418, CHD5
references
1: Seelig, H. P., I.
Moosbrugger, et al. (1995). The major
dermatomyositis-specific Mi-2 autoantigen is a
presumed helicase involved in transcriptional
activation. Arthritis Rheum 38(10): 1389-99.
PubMed
2: Bowen, N. J., N.
Fujita, et al. (2004). Mi-2/NuRD: multiple
complexes for many purposes. Biochim Biophys
Acta 1677(1-3): 52-7.
PubMed
3: Schultz, D. C., J. R.
Friedman, et al. (2001). Targeting histone
deacetylase complexes via KRAB-zinc finger
proteins: the PHD and bromodomains of KAP-1 form
a cooperative unit that recruits a novel isoform
of the Mi-2alpha subunit of NuRD. Genes Dev
15(4): 428-43.
PubMed
4: Korenjak, M., B.
Taylor-Harding, et al. (2004). Native E2F/RBF
complexes contain Myb-interacting proteins and
repress transcription of developmentally
controlled E2F target genes. Cell 119(2):
181-93.
PubMed
5: Bouazoune, K., A.
Mitterweger, et al. (2002). The dMi-2
chromodomains are DNA binding modules important
for ATP-dependent nucleosome mobilization. Embo
J 21(10): 2430-40.
PubMed
6: Thompson, P. M., T.
Gotoh, et al. (2003). CHD5, a new member of the
chromodomain gene family, is preferentially
expressed in the nervous system. Oncogene 22(7):
1002-11.
PubMed
7: White, P. S., P. M.
Thompson, et al. (2005). Definition and
characterization of a region of 1p36.3
consistently deleted in neuroblastoma. Oncogene
24(16): 2684-94.
PubMed
8: Ogas, J., S. Kaufmann,
et al. (1999). PICKLE is a CHD3
chromatin-remodeling factor that regulates the
transition from embryonic to vegetative
development in Arabidopsis. Proc Natl Acad Sci U
S A 96(24): 13839-44.
PubMed
