FAMILY WITH SEQUENCE SIMILARITY 129, MEMBER B; FAM129B

Alternative titles; symbols

• MELANOMA INVASION BY ERK; MINERVA

HGNC Approved Gene Symbol: NIBAN2

Cytogenetic location: 9q34.11 Genomic coordinates (GRCh38): 9:127,505,338-127,579,030 (from NCBI)

▼ Cloning and Expression
Chen et al. (2011) cloned human FAM129B. The deduced 746-amino acid protein has a calculated molecular mass of 83 kD. It contains an N-terminal pleckstrin (PLEK; 173570) homology (PH) domain, a C-terminal proline-rich domain, and 6 potential serine phosphorylation sites. In growing HeLa cells and mouse embryonic fibroblasts, FAM129B localized to the cytoplasmic compartment. In confluent HeLa cells, FAM129B relocalized to the plasma membrane near cell junctions.

▼ Gene Function
Chen et al. (2011) found that knockdown of FAM129B in HeLa cells did not itself induce apoptosis, but it accelerated the onset of apoptosis induced by TNF-alpha (TNF; 191160). Apoptosis proceeded through a caspase (see 600636)-dependent and proteasome-independent pathway, and FAM129B was degraded during apoptosis. In melanoma and HeLa cells, FAM129B localized to the cytoplasm during an active ERK1 (MAPK3; 601795)/ERK2 (MAPK1; 176948) MAP kinase cascade. FAM129B localized to cell junctions upon inhibition of the MAP kinase cascade and upon growth to confluence. FAM129B also localized to the plasma membrane during mitosis.

▼ Gene Structure
Chen et al. (2011) determined that the FAM129B gene contains 3 exons.

▼ Mapping
Hartz (2011) mapped the FAM129B gene to chromosome 9q34.13 based on an alignment of the FAM129B sequence (GenBank AL137555) with the genomic sequence (GRCh37).