Disease relevance of HNRPF

• Additionally, they suggest that hnRNP F is a potential marker for colorectal cancer progression [1].
• Altered expression and localization of creatine kinase B, heterogeneous nuclear ribonucleoprotein F, and high mobility group box 1 protein in the nuclear matrix associated with colon cancer [1].
• Mcs94-1 was examined as a candidate for MEN2A through nucleotide sequence analysis of mcs94-1 exons from an MEN 2A chromosome and its wildtype homologue from an MEN 2A patient [2].
• The binding of the CstF2 (64 kDa cleavage stimulatory factor) to SV40 (simian virus 40) late pre-mRNA substrates containing a downstream GRS (guanine-rich sequence) was reduced by hnRNP F, but not by hnRNP H2, in a UV-cross-linking assay [3].

High impact information on HNRPF

• This 75-kD protein induces the assembly of five other proteins, including the heterogeneous nuclear ribonucleoprotein F, onto the splicing enhancer [4].
• In this study, we show that transportin mediates the nuclear import of additional hnRNP proteins, including hnRNP F [5].
• The sumoylation of hnRNP A1, hnRNP F, and hnRNP K were confirmed in vivo by coimmunoprecipitation [6].
• First, by Western analyses of cellular proteins, the ratio of hnRNP F to H or H' was found to be higher in memory B cells than in plasma cells [7].
• Fourth, overexpression of recombinant hnRNP F in plasma cells resulted in a decrease in the endogenous Ig heavy-chain mRNA secretory form-to-membrane ratio [7].

Biological context of HNRPF

• Finally, in vitro binding assays demonstrate that hnRNP H can interact with the related protein hnRNP F, suggesting that hnRNPs H and F may exist as a heterodimer in a single enhancer complex [8].
• Using four complementary approaches, we demonstrate that a change in the level of hnRNP F is an important determinant in the regulated use of alternative polyadenylation sites between memory and plasma stage B cells [7].
• The predicted amino acid sequence of hnRNP F revealed a novel protein with three repeated domains related to the RNP consensus sequence RNA-binding domain [9].
• The tissue distribution profile of hnRNP-F was similar to that of both RNA pol II and TBP [10].
• 2. An evolutionarily conserved sequence from D10S94 was used as a probe to isolate cDNAs corresponding to a gene that we have termed mcs94-1 [2].

Anatomical context of HNRPF

• Depletion of hnRNP F from HeLa cell nuclear extract decreases the efficiency of pre-mRNA splicing, a defect which can be partially compensated by addition of recombinant hnRNP F [11].
• hnRNP F influences binding of a 64-kilodalton subunit of cleavage stimulation factor to mRNA precursors in mouse B cells [7].
• The subcellular fractions studied both showed high protein levels of hnRNP F in colon tumors compared with normal colon tissues [1].
• Generally, hnRNP F is broadly expressed in many tissues with extremely strong expression in the prostate gland while hnRNP H/H' shows a more restricted degree of expression with low expression in some tissues, for example, liver, exocrine acini of the pancreas, thyroid gland and heart [12].

Associations of HNRPF with chemical compounds

• The unique RNA-binding properties, amino acid sequence and distinct intranuclear localization of hnRNP F and hnRNP H make them novel hnRNP proteins that are likely to be important for the processing of RNAs containing guanosine-rich sequences [9].
• Protein 2H9 displays two consensus sequence-type RNA binding domains (CS-RBD) showing 80-90% homology with two of the three CS-RBDs of hnRNP F and H/H'. Another common feature is the presence of two glycine/tyrosine-rich auxiliary domains located at the C terminus and between the two CS-RBDs [13].

Physical interactions of HNRPF

• Moreover, hnRNP K interacted with hnRNP F in pulldown and co-immunoprecipitation assays [14].

Other interactions of HNRPF

• The most prominent components of this enhancer complex are the proteins hnRNP F, KSRP, and an unidentified protein of 58 kDa (p58) [8].
• These results suggest an involvement of hnRNP F and CKB in colorectal cancer [1].
• Interestingly, immunofluorescence microscopy revealed that hnRNP F and hnRNP H are concentrated in discrete regions of the nucleoplasm, in contrast to the general nucleoplasmic distribution of previously characterized hnRNP proteins [9].
• Curiously, the domain organization of GRSF-1 is similar to the RNA binding proteins PUB1, ELAV, HuD, Hel-N1, mcs94-1 and RBP9 [15].

References