- OMIM ID: 609691
- OMIM diseaseName:
- OMIM diseaseClinical_Synopsis:
- OMIM diseaseText:
Proteins that contain formin (FMN1; 136535) homology (FH) domains, such
as FHOD3, play a role in regulation of the actin cytoskeleton (Kanaya et
By sequencing clones obtained from a size-fractionated fetal brain cDNA
library, Nagase et al. (2000) cloned FHOD3, which they designated
KIAA1695. The deduced protein contains 1,199 amino acids. RT-PCR ELISA
detected highest expression in heart, followed by fetal brain and adult
skeletal muscle. Intermediate expression was detected in all other whole
tissues and specific brain regions examined.
By searching for sequences similar to FHOD1 (606881) Katoh and Katoh
(2004) identified 3 FHOD3 alternative splice variants. One variant
encodes the full-length protein, while the other variants, KIAA1695 and
FLJ34580, lack exon 11 and exon 13, respectively. The deduced
full-length protein contains 1,439 amino acids and has a central FH1
domain and a C-terminal FH2 domain. FHOD3 shares 52.1% amino acid
identity with FHOD1 and 43.9% amino acid identity with the Drosophila
FHOD3 ortholog. In addition to the FH1 and FH2 domains, these proteins
have conserved N- and C-terminal domains that the authors designated
FHDHN and FHDHC, respectively.
By searching an EST database for sequences similar to FHOD1, followed by
screening a human fetal brain cDNA library, RT-PCR, and 5-prime RACE,
Kanaya et al. (2005) cloned FHOD3, which they designated FHOS2. The
deduced protein contains 1,422 amino acids. Kanaya et al. (2005) also
identified 2 splice variants of mouse Fhos2, designated Fhos2l and
Fhos2s, that encode proteins of 1,578 and 1,427 amino acids,
respectively, and differ by the presence or absence of a sequence in the
N-terminal half. Fhos2s shares 91% amino acid identity with human FHOS2.
Northern blot analysis of several mouse tissues detected abundant Fhos2
expression in heart and kidney, much lower expression in brain, and
little to no expression in other tissues. Fhos2s was expressed in kidney
and brain, whereas Fhos2l predominated in heart. The pattern of FHOS2
expression in human tissues was similar. Immunocytochemical analysis of
rat embryonal cardiomyocytes detected colocalization of Fhos2 with
nestin (NES; 600915), an intermediate filament protein. In fetal rat
brain, Fhos2 localized to radial fibers extending from the ventricle
surface to the pial surface. In medulla oblongata, it localized to
radial processes extending from the surface of the fourth ventricle. In
developing heart, Fhos2 localized to I-band structures. Fhos2 partially
localized with nestin in developing brain, but not in developing heart.
Kanaya et al. (2005) noted that FHOS1 seems to be normally folded in an
inactive form maintained by an intramolecular interaction between its N-
and C-terminal regions. Deletion of the N- or C terminal regions
activates FHOS1, inducing stress fiber formation. Kanaya et al. (2005)
therefore overexpressed C-terminally truncated forms of mouse Fhos2l and
Fhos2s in HeLa cells and found that both induced stress fiber formation
and cell elongation. C-terminally truncated Fhos2s localized to actin
filaments, whereas C-terminally truncated Fhos2l did not.
Katoh and Katoh (2004) determined that the FHOD3 gene contains at least
By genomic sequence analysis, Katoh and Katoh (2004) mapped the FHOD3
gene to chromosome 18q12.2.
- OMIM diseaseSee_Also:
- OMIM diseaseAllelic_Variants:
- OMIM diseaseCreation_Date: Patricia A. Hartz: 10/27/2005
- OMIM diseaseEdit_History_Data: wwang: 04/02/2010
- OMIM diseaseContributors:
- OMIM diseaseReference: 1. Kanaya, H.; Takeya, R.; Takeuchi, K.; Watanabe, N.; Jing, N.; Sumimoto,
H.: Fhos2, a novel formin-related actin-organizing protein, probably
associates with the nestin intermediate filament. Genes Cells 10:
2. Katoh, M.; Katoh, M.: Identification and characterization of human
FHOD3 gene in silico. Int. J. Molec. Med. 13: 615-620, 2004.
3. Nagase, T.; Kikuno, R.; Hattori, A.; Kondo, Y.; Okumura, K.; Ohara,
O.: Prediction of the coding sequences of unidentified human genes.
XIX. The complete sequences of 100 new cDNA clones from brain which
code for large proteins in vitro. DNA Res. 7: 347-355, 2000.