Cloning and functional identification of a novel BCA3 splice

Abstract

ABSTRACT. The human breast cancer-associated gene (BCA3) was first discovered in breast and prostate cancer cells lines. In vivo studies have shown that BCA3 is mainly expressed in breast tumor cells and not in normal breast and prostate tissues. To date, 3 splice variants of BCA3 have been reported: a double-absent variant lacking exon 3 and exon 5 (BCA3-1), an exon 3-absent variant (BCA3-2), and full-length BCA3. In this study, we investigated whether a novel BCA3 splice variant exists that lacks only the exon 5-encoding sequence. BCA3 variant splices were subcloned and sequenced using reverse transcription-polymerase chain reaction. The preliminary biological functions of the splices were identified using confocal microscopy and a luciferase assay. The absence of exon 3 and exon 5 influenced the subcellular localization of BCA3 and nuclear factor kappa B (NF-kB)-dependent gene expression. Exon 3 and exon 5 of BCA3 may function together to provide a nuclear localization signal or transport sequence to enter the nucleus, and exon 3 may contain specific sequence(s) or domain(s) that influence the NF-κB signal cascade. The discovery of 10649 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (4): 10648-10656 (2014) Novel BCA3 splice novel BCA3 splicing indicates a new cancer research area, which may increase the understanding of cancer generation and development.

Various AKIP1 Expression Levels Affect Its Subcellular Localization but Have no Effect on NF-κB Activation

“…Nevertheless, neither highly nor lowly expressed AKIP1 enhanced NF-κB activity. This finding contrasts with previous works by Zhang et al (2014) or Gao et al Vol. 68 (2008), in which the same cell line (HEK-293) and the same dual reporter assay (DLR) were used and AKIP1 was expressed from a similar expression plasmid, pcDNA3.1-FLAG.…”

“…AKIP1, PKAc, inhibitor of NF-κB (IκB) and p65 subunit of NF-κB form an inactive cytosolic complex that may be Vol. 68 modulated through PKA activators (Zhang et al 2014). Phosphorylation of p65 subunit by PKA is essential for the activation and translocation of NF-κB p65/p50 into the nucleus where it regulates transcription of target genes (Hayden andGhosh 2008, Gilmore 2006).…”

“…AKIP1 overexpression in HEK-293 cells has been shown to modulate NF-κB transcriptional activity by regulating the nuclear localization of the p65 subunit as well as by promoting the phosphorylation of p65 by the PKAc (Gao et al 2010, King et al 2011. However, contradictory results have been reported regarding the role of AKIP1 in regulation of NF-κB p65/p50-dependent transcription (Gao et al 2006, Gao et al 2008, Zhang et al 2014.…”

PKA and AKIP1 interact to mediate cAMP-driven COX-2 expression: A potentially pivotal interaction in preterm and term labour

“…Previous work has investigated the effects of AKIP1 in breast cancer cells [ 16 ], but to date, this has not been investigated in myometrium. As labour is believed to be an inflammatory process, AKIP1 may function as a molecular switch in myometrium, promoting NFκB activitation; It has been reported that in breast cancer tissue there are at least three different splice variants of AKIP1 [ 26 ], further more these have distinct cellular localization [ 27 ] and different affinity binding for PKAc [ 28 ] and such could have an impact of NFκB activation. It would be beneficial, to investigate in more detail if and how the splicing of AKIP1 changes during in parturition.…”