Influenza A, Texas 1/77 (KPNA1) Antibody – Goat Polyclonal

The transport of molecules between the nucleus and the cytoplasm in eukaryotic cells is mediated by the nuclear pore complex (NPC), which consists of 60-100 proteins. Small molecules (up to 70 kD) can pass through the nuclear pore by nonselective diffusion while larger molecules are transported by an active process. The protein encoded by this gene belongs to the importin alpha family, and is involved in nuclear protein import. This protein interacts with the recombination activating gene 1 (RAG1) protein and is a putative substrate of the RAG1 ubiquitin ligase. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2012]

KPNA1: Functions in nuclear protein import as an adapter protein for nuclear receptor KPNB1. Binds specifically and directly to substrates containing either a simple or bipartite NLS motif. Docking of the importin/substrate complex to the nuclear pore complex (NPC) is mediated by KPNB1 through binding to nucleoporin FxFG repeats and the complex is subsequently translocated through the pore by an energy requiring, Ran- dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to importin-beta and the three components separate and importin-alpha and -beta are re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran from importin. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus. In vitro, mediates the nuclear import of human cytomegalovirus UL84 by recognizing a non- classical NLS. Belongs to the importin alpha family.

Protein type: Adaptor/scaffold; Nuclear import; Karyopherin

Chromosomal Location of Human Ortholog: 3q21

Cellular Component: nucleoplasm; dendrite; cytoplasm; nuclear pore; cytosol; nucleus

Molecular Function: protein binding; nuclear localization sequence binding; protein transporter activity

Biological Process: positive regulation of protein import into nucleus; viral reproduction; apoptosis; regulation of DNA recombination; cytokine and chemokine mediated signaling pathway; viral infectious cycle; NLS-bearing substrate import into nucleus; DNA fragmentation during apoptosis; cell structure disassembly during apoptosis