Alternative titles; symbols
HGNC Approved Gene Symbol: SSX2IP
Cytogenetic location: 1p22.3 Genomic coordinates (GRCh38) : 1:84,643,706-84,690,745 (from NCBI)
By sequencing clones obtained from a size-fractionated brain cDNA library, Nagase et al. (1999) cloned SSX2IP, which they designated KIAA0923. The 3-prime UTR contains MIR sequences, and the deduced protein contains 614 amino acids. RT-PCR ELISA detected highest expression in brain, intermediate expression in kidney, testis, spinal cord, liver, heart, lung, skeletal muscle, ovary, fetal liver, and fetal brain, and little to no expression in pancreas and spleen. All specific brain regions showed intermediate to high expression, with highest expression in amygdala.
Using SSX2 (300192) as bait in a yeast 2-hybrid screen of a testis cDNA library, followed by conventional screening, de Bruijn et al. (2002) cloned SSX2IP. The deduced 614-amino acid protein has a calculated molecular mass of 71 kD. SSX2IP contains 4 coiled-coil domains, a putative phosphate-binding P loop, and a bipartite nuclear localization signal. It also has potential sites for N-glycosylation, phosphorylation, N-myristoylation, and amidation. Northern blot analysis of adult and fetal tissues detected ubiquitous expression of 4.0-, 6.0-, and 6.7-kb transcripts, with highest expression in adult brain. SDS-PAGE of in vitro transcribed and translated SSX2IP cDNA revealed doublet protein bands with apparent molecular masses of 64 and 68 kD.
Using afadin (159559) as bait in a yeast 2-hybrid screen of an embryonic mouse cDNA library, Asada et al. (2003) cloned Ssx2ip, which they designated Adip. The deduced protein contains 615 amino acids. Northern and Western blot analyses of mouse tissues indicated that Adip is widely distributed. Immunofluorescence and immunoelectron microscopy revealed that Adip strictly localized at cell-cell adherens junctions undercoated with F-actin (see 102610) bundles in small intestine absorptive epithelial cells.
By in vitro pull-down assays, de Bruijn et al. (2002) confirmed the interaction between SSX2IP and SSX2. SSX2IP specifically interacted with an N-terminal domain of SSX2. It also interacted with SSX3 (300325), but not with SSX1 (312820) or SSX4 (300326).
Asada et al. (2003) found that mouse Adip bound alpha-actinin (see 102575) and afadin. They hypothesized that Adip may be involved in organization of the actin cytoskeleton at adherens junctions through afadin and alpha-actinin.
De Bruijn et al. (2002) determined that the SSX2IP gene contains 14 exons and spans more than 46 kb. The first exon is embedded in a predicted CpG island, and there is no consensus TATA box, characteristics of a housekeeping gene.
By radiation hybrid analysis, Nagase et al. (1999) mapped the SSX2IP gene to chromosome 1. By FISH, de Bruijn et al. (2002) mapped the SSX2IP gene to chromosome 1p22.
Asada, M., Irie, K., Morimoto, K., Yamada, A., Ikeda, W., Takeuchi, M., Takai, Y. ADIP, a novel afadin- and alpha-actinin-binding protein localized at cell-cell adherens junctions. J. Biol. Chem. 278: 4103-4111, 2003. [PubMed: 12446711] [Full Text: https://doi.org/10.1074/jbc.M209832200]
de Bruijn, D. R. H., dos Santos, N. R., Kater-Baats, E., Thijssen, J., van den Berk, L., Stap, J., Balemans, M., Schepens, M., Merkx, G., van Kessle, A. G. The cancer-related protein SSX2 interacts with the human homologue of a Ras-like GTPase interactor, RAB3IP, and a novel nuclear protein, SSX2IP. Genes Chromosomes Cancer 34: 285-298, 2002. [PubMed: 12007189] [Full Text: https://doi.org/10.1002/gcc.10073]
Nagase, T., Ishikawa, K., Suyama, M., Kikuno, R., Hirosawa, M., Miyajima, N., Tanaka, A., Kotani, H., Nomura, N., Ohara, O. Prediction of the coding sequences of unidentified human genes. XIII. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro. DNA Res. 6: 63-70, 1999. [PubMed: 10231032] [Full Text: https://doi.org/10.1093/dnares/6.1.63]