Disease relevance of PEF1

• We have previously identified a novel cellular transcription factor, PEF-1, from its ability to interact with the long control region (LCR) of HPV-16 [1].

High impact information on PEF1

• These results suggest that peflin has features common to those of other PEF proteins (dimerization and translocation to membranes) and may modulate the function of ALG-2 in Ca(2+) signaling [2].
• Peflin was recovered in the cytosolic fraction in the absence of Ca(2+) but in the membrane/cytoskeletal fraction in the presence of Ca(2+) [2].
• We have shown that fp5e is crucial to enhancer function and have described an apparently novel factor (PEF-1) binding fp5e (S. Cuthill, G. J. Sibbet, and M. S. Campo, Mol. Carcinog. 8:9-104, 1993) [3].
• Sp1 is O-glycosylated while PEF-1 appears to have a novel type of glycosylation, as shown by the interaction with pokeweed lectin and by the inhibition of this interaction by tunicamycin [1].
• PEF-1, an epithelial cell transcription factor which activates the long control region of human papillomavirus type 16, is glycosylated with N-acetylglucosamine [1].

Biological context of PEF1

• Both ALG-2 and peflin, penta-EF-hand (PEF) proteins, are stabilized by dimerization through their fifth EF-hand regions [4].
• We isolated a cDNA clone of near full length by 5'- and 3'-RACE (rapid amplification of cDNA end) methods and compared the predicted amino acid sequence (284 residues) of the novel EF-hand protein, named peflin, with those of known PEF proteins [5].
• We show that PEF-1 and Sp1 are distinct transcription factors: they recognize different DNA sequences, have different electrophoretic mobilities and different glycosylation patterns [1].
• The PEF-1 binding site is centered around a CCAAT box-like CCAAC element [6].
• PEF-1 has an apparent molecular weight of about 110 kDa, and we propose that it is a novel factor involved in the transcriptional activation of HPV-16 gene expression [6].

Anatomical context of PEF1

• Gel filtration of the cytosolic fraction of Jurkat cells revealed co-elution of peflin and ALG-2 in fractions eluting earlier than recombinant ALG-2, further supporting the notion of heterodimerization of the two PEF proteins [2].
• Western blot analysis demonstrated that peflin (30 kDa) was expressed in various nonadherent and adherent cultured human cell lines, including Jurkat, HL60, HeLa, and HT1080 [5].

Analytical, diagnostic and therapeutic context of PEF1

• This was confirmed by Western blotting of the immunoprecipitates of epitope-tagged peflin or ALG-2 whose cDNA expression constructs were transfected to human embryonic kidney (HEK) 293 cells [2].

References