SummaryA rice genic male-sterility gene ms-h is recessive and has a pleiotropic effect on the chalky endosperm. After fine mapping, nucleotide sequencing analysis of the ms-h gene revealed a single nucleotide substitution at the 3¢-splice junction of the 14th intron of the UDP-glucose pyrophosphorylase 1 (UGPase1; EC2.7.7.9) gene, which causes the expression of two mature transcripts with abnormal sizes caused by the aberrant splicing. An in vitro functional assay showed that both proteins encoded by the two abnormal transcripts have no UGPase activity. The suppression of UGPase by the introduction of a UGPase1-RNAi construct in wild-type plants nearly eliminated seed set because of the male defect, with developmental retardation similar to the ms-h mutant phenotype, whereas overexpression of UGPase1 in ms-h mutant plants restored male fertility and the transformants produced T 1 seeds that segregated into normal and chalky endosperms. In addition, both phenotypes were co-segregated with the UGPase1 transgene in segregating T 1 plants, which demonstrates that UGPase1 has functional roles in both male sterility and the development of a chalky endosperm. Our results suggest that UGPase1 plays a key role in pollen development as well as seed carbohydrate metabolism.

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BACKGROUND Although alpha‐fetoprotein (AFP) is a useful serologic marker of hepatocellular carcinoma (HCC), it has been reported insufficiently sensitive in detecting small HCCs. Plasma transforming growth factor‐β1 (TGFβ1) has been reported to be elevated in HCC patients compared with liver cirrhosis patients. It has been reported that TGFβ1 mRNA was overexpressed in HCC, especially in patients with small HCC and well‐differentiated HCC compared with patients with liver cirrhosis. The current study investigated the usefulness of TGFβ1 compared with AFP in the diagnosis of small HCCs. METHODS Thirty‐eight patients with small HCC (≤ 3 cm), 31 patients with liver cirrhosis only, and 23 normal volunteers were studied. Using plasma TGFβ1 and serum AFP levels measured at the time of diagnosis, the sensitivities and specificities were calculated in the diagnosis of small HCCs. RESULTS Plasma TGFβ1 and serum AFP levels were significantly higher in patients with small HCC than in those with liver cirrhosis. In diagnosing small HCCs, the cut‐off values of plasma TGFβ1 and serum AFP were 800pg/mL and 200ng/mL, respectively, where the specificities were over 95%. At the cut‐off level of plasma TGFβ1 and serum AFP, the sensitivities were 68% and 24%, respectively. CONCLUSIONS The current results suggest that TGFβ1 may be a useful serologic marker in detecting HCCs earlier because it shows higher sensitivity than, with specificity as, AFP in the diagnosis of small HCCs. Cancer 2002;94:175–80. © 2002 American Cancer Society.

Supramolecular protein assemblies offer novel nanoscale architectures with molecular precision and unparalleled functional diversity. A key challenge, however, is to create precise nano-assemblies of functional proteins with both defined structures and a controlled number of protein-building blocks. Here we report a series of supramolecular green fluorescent protein oligomers that are assembled in precise polygonal geometries and prepared in a monodisperse population. Green fluorescent protein is engineered to be self-assembled in cells into oligomeric assemblies that are natively separated in a single-protein resolution by surface charge manipulation, affording monodisperse protein (nano)polygons from dimer to decamer. Several functional proteins are multivalently displayed on the oligomers with controlled orientations. Spatial arrangements of protein oligomers and displayed functional proteins are directly visualized by a transmission electron microscope. By employing our functional protein assemblies, we provide experimental insight into multivalent protein–protein interactions and tools to manipulate receptor clustering on live cell surfaces.