Karyopherin subunit alpha 2 (KPNA2) (KPNA2)

Karyopherin subunit alpha 2 (KPNA2), frequently referred to as Importin alpha 2 or Importin subunit alpha-1, is a pivotal adaptor protein within the classical nuclear import machinery. It functions by identifying and binding to nuclear localization signals (NLS) on a wide array of cargo proteins, including transcription factors and cell cycle regulators, and facilitating their transport into the nucleus in partnership with Importin beta 1 (PubMed: 22808339, 32130408). Beyond its fundamental transport role, KPNA2 is involved in critical cellular processes such as DNA damage repair, spindle assembly during mitosis, and the regulation of apoptosis (PubMed: 23152447, 28991411). In clinical oncology, KPNA2 is recognized as a significant oncogene and prognostic biomarker, as its overexpression is strongly correlated with increased tumor aggressiveness, metastasis, and poor survival across various cancers, including breast, lung, and colorectal carcinomas (PubMed: 23152447, 31942031). Furthermore, KPNA2 is exploited by numerous viruses, such as SARS-CoV-2 and HIV-1, to transport viral components into the host nucleus or to disrupt host innate immune signaling, making it a target of interest for both antiviral and anticancer therapeutic strategies (PubMed: 32130408, 34103406). Despite its therapeutic potential, the essential nature of KPNA2 in maintaining normal cellular homeostasis poses a significant challenge for the development of selective inhibitors with minimal off-target effects.

Other names

Importin alpha 2Importin subunit alpha-1RAG cohort protein 1RCH1SRP1-alphaPendulinPTAC58QIP2

Acts as an adaptor protein that recognizes and binds to classical nuclear localization signals (cNLS) on cargo proteins in the cytoplasm, subsequently forming a trimeric complex with Importin beta 1 (KPNB1) to facilitate translocation through the nuclear pore complex into the nucleus (PubMed: 7604027, 21690087).