Disease relevance of Hnrpa1

• Retroviral insertions downstream of the heterogeneous nuclear ribonucleoprotein A1 gene in erythroleukemia cells: evidence that A1 is not essential for cell growth [1].
• Regulation of mouse hepatitis virus RNA synthesis by heterogeneous nuclear ribonucleoprotein A1 [2].
• Evaluation of the role of heterogeneous nuclear ribonucleoprotein A1 as a host factor in murine coronavirus discontinuous transcription and genome replication [3].

High impact information on Hnrpa1

• Here, it is shown that the heterogeneous nuclear ribonucleoprotein A1 participates in telomere biogenesis [4].
• The deduced amino acid sequence of a cDNA corresponding to a transcript originating from genomic DNA adjacent to Fli-2 is identical to that of the human heterogeneous nuclear ribonucleoprotein A1 gene, a member of the gene family of RNA-binding proteins involved in RNA splicing [1].
• S-nitrosylation of heterogeneous nuclear ribonucleoprotein A/B regulates osteopontin transcription in endotoxin-stimulated murine macrophages [5].
• Interestingly, T cell receptor-triggered translocation is selective as heterogeneous nuclear ribonucleoprotein A1 does not shuttle under the same conditions [6].
• This study shows that MARs recruit and bind hnRNP-A1 upon transcriptional up-regulation [7].

Biological context of Hnrpa1

• The heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) functions in the packaging of nascent RNA polymerase II transcripts and participates in a variety of nuclear and cytoplasmic processes that modulate gene expression [8].
• Recruitment of heterogeneous nuclear ribonucleoprotein A1 in vivo to the LMP/TAP region of the major histocompatibility complex [7].
• A strong hnRNP A1-binding site was located 90 to 170 nucleotides from the 3' end of MHV RNA, and a weak binding site was mapped at nucleotides 260 to 350 from the 3' end [9].
• A heterogeneous nuclear ribonucleoprotein A/B-related protein binds to single-stranded DNA near the 5' end or within the genome of feline parvovirus and can modify virus replication [10].
• We have developed a simple lipofection method for high efficiency transfection and stable transgene expression by employing the nonclassical nuclear localization signal M9 derived from the heterogeneous nuclear ribonucleoprotein A1 [11].

Anatomical context of Hnrpa1

• Finally, we show that hnRNP A1 can be overexpressed in mouse primary hepatocytes, leading to an accumulation of the CYP2A5 mRNA [8].

Associations of Hnrpa1 with chemical compounds

• We also show that a specific hepatotoxic inducer of the Cyp2a5 gene, pyrazole, increases the cytoplasmic levels of hnRNP A1 in vivo [8].
• Yeast two-hybrid assays further indicated in vivo that such binding relates to the fragment (aa 161-210) of SARS_N and the Gly-rich domain (aa 203-320) of hnRNP A1 [12].

Physical interactions of Hnrpa1

• In this article, we show that hnRNP A1 interacts with the transcript of a cytochrome P450 gene, Cyp2a5, induced by xenobiotics and during liver damage [8].

Other interactions of Hnrpa1

• Collectively, these results indicate that the hnRNP A1 is an important regulator of the Cyp2a5 gene [8].

Analytical, diagnostic and therapeutic context of Hnrpa1

• Binding of the hnRNP A1 to CYP2A5 mRNA was demonstrated by immunoprecipitation of the xenobiotic-stimulated (37/39 kDa) CYP2A5 mRNA-protein complex with a monoclonal anti-hnRNP A1 antibody, by partial trypsin digestion of the complex, and by showing that the RNA-protein complex is not formed with protein extracts from cells lacking the hnRNP A1 [8].
• Moreover, kinetic analyses by surface plasmon resonance (SPR) technology revealed that SARS_N protein has a specific binding affinity against human hnRNP A1 with K(D) at 0.35 +/- 0.02 microM (k(on) = 5.83 +/- 0.42 x 10(3) M(-1)s(-1) and k(off) = 2.06 +/- 0.12 x 10(-3)s(-1)) [12].

References