High impact information on HNRPDL

• An antiserum raised to the conceptual reading frame of HNRNP G-T showed that it encodes a protein that is highly expressed in germ cells and in particular in the nuclei of meiotic spermatocytes [1].
• However, unlike many retroposon-derived genes, HNRNP G-T is not a pseudogene [1].
• We have identified a new member of this gene family, HNRNP G-T, and have mapped it as a single-copy gene on chromosome 11 [1].
• In differentiated myotubes, heterogeneous nuclear ribonucleoprotein D-like protein/JKTBP1 bound to the CATR motif exclusive of YY-1 and interacted with ZBP-89 in attenuating repressor activity, leading to transcription activation [2].
• We discuss a role of JKTBP in mRNA nuclear export [3].

Biological context of HNRPDL

• Isolation and characterization of the genomic DNA showed that the gene (HNRPDL) had nine exons and had two separate transcription start sites for the two transcripts [4].
• JKTBP proteins are related to a family of heterogeneous nuclear ribonucleoproteins (hnRNPs) that function in mRNA biogenesis and mRNA metabolism [3].
• For examination of RNA binding specificity of JKTBP, we enriched high binding sites from pools of 20 nt random sequence-containing RNAs by a selection/amplification method [5].
• These results indicate that JKTBP is a sequence-specific RNA binding protein differing from the related heterogeneous nuclear ribonucleoproteins A1 and D [5].
• Nevertheless, the R100H mutation detected suggests that in some men mutations in the HNRNP G-T gene can cause impaired spermatogenesis [6].

Anatomical context of HNRPDL

• Immunofluorescence microscopy and immunoblotting of the subcellular fractions and overexpression of JKTBP tagged with green fluorescent protein indicated that JKTBP1 and JKTBP1Delta6, but not JKTBP2, accumulate in the cytoplasm upon polymerase II transcription inhibition [3].

Physical interactions of HNRPDL

• JKTBP proteins consisting of two canonical RNA binding domains (RBDs) and a glycine-rich carboxyl domain are nucleocytoplasmic shuttling proteins [5].

Other interactions of HNRPDL

• Analysis of its sequence-specific interacting protein indicated that JKTBP nuclear import is mediated by the receptor transportin 1/karyopherin beta2 [3].
• Using the differential display method, a new cDNA clone, termed laAUF1, encoding the human A + U-rich RNA-binding motif was isolated and sequenced [7].

References