HOP Homeobox (HOPX) Human Recombinant Protein

The protein encoded by this gene is a homeodomain protein that lacks certain conserved residues required for DNA binding. It was reported that choriocarcinoma cell lines and tissues failed to express this gene, which suggested the possible involvement of this gene in malignant conversion of placental trophoblasts. Studies in mice suggest that this protein may interact with serum response factor (SRF) and modulate SRF-dependent cardiac-specific gene expression and cardiac development. Multiple alternatively spliced transcript variants have been identified for this gene. [provided by RefSeq, Feb 2009]

HOPX: Atypical homeodomain protein which does not bind DNA and is required to modulate cardiac growth and development. Acts via its interaction with SRF, thereby modulating the expression of SRF-dependent cardiac-specific genes and cardiac development. Prevents SRF-dependent transcription either by inhibiting SRF binding to DNA or by recruiting histone deacetylase (HDAC) proteins that prevent transcription by SRF. Overexpression causes cardiac hypertrophy. May act as a tumor suppressor. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Oncoprotein; DNA-binding

Chromosomal Location of Human Ortholog: 4q12

Cellular Component: nucleus

Molecular Function: DNA binding

Biological Process: negative regulation of cell differentiation; transcription, DNA-dependent; positive regulation of skeletal muscle regeneration; regulation of protein binding; heart development; histone deacetylation; negative regulation of transcription from RNA polymerase II promoter; positive regulation of striated muscle cell differentiation; alveolus development; regulation of heart contraction; trophectodermal cell differentiation