NF-Y recruitment of TFIID, multiple interactions with histone fold TAF(II)s

The nuclear factor y (NF-Y) trimer and TFIID contain histone fold subunits, and their binding to the CCAAT and Initiator elements of the major histocompatibility complex class II Ea promoter is required for transcriptional activation. Using agarose-electrophoretic mobility shift assay we found that NF-Y increases the affinity of holo-TFIID for Ea in a CCAAT- and Inr-dependent manner. We began to dissect the interplay between NF-Y- and TBP-associated factors PO1II (TAF(II)s)-containing histone fold domains in protein-protein interactions and transfections. hTAF(II)20, hTAF(II)28, and hTAF(II)18-hTAF(II)28 bind to the NF-Y B-NF-YC histone fold dimer; hTAF(II)80 and hTAF(II)31-hTAF(II)80 interact with the trimer but not with the NF-YB-NF-YC dimer. The histone fold alpha2 helix of hTAF(II)80 is not required for NF-Y association, as determined by interactions with the naturally occurring splice variant hTAF(II)80delta. Expression of hTAF(II)28 and hTAF(II)18 in mouse cells significantly and specifically reduced NF-Y activation in GAL4-based experiments, whereas hTAF,120 and hTAF(II)135 increased it. These results indicate that NF-Y (i) recruits purified holo-TFIID in vitro and (ii) can associate multiple TAF(II)s, potentially accommodating different core promoter architectures

Colonic malacoplakia: Unusual association with ulcerative colitis

A 44 year old Chinese female with malacoplakia of the colon associated with ulcerative colitis was presented. The patient showed typical histological, electron microscopic and X-ray micro-analysis findings of malacoplakia. The malacoplakia gradually disappeared after discontinuation of high-dose systemic steroid prescribed by private practitioner for the ulcerative colitis. A review of the 26 previously reported cases of malacoplakia of the colon is also included. Coupled with the clinical events of this patient, it appears that malacoplakia is likely to be secondary to immunosuppression, due to drugs, malignant or debilitating diseases.link_to_subscribed_fulltex