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We purified a novel actin filament (F-actin)-binding protein from the soluble fraction of Saccharomyces cerevisiae by successive column chromatographies by use of the 125I-labeled F-actin blot overlay method. The purified protein showed a minimum Mr of about 140 kDa on SDS-polyacrylamide gel electrophoresis and we named it ABP140. A search with the partial amino acid sequences of ABP140 against the Saccharomyces Genome Database revealed that the open reading frame of the ABP140 gene (ABP140) corresponded to YOR239W fused with YOR240W by the +1 translational frame shift. The encoded protein consisted of 628 amino acids with a calculated Mr of 71,484. The recombinant protein interacted with F-actin and showed the activity to crosslink F-actin into a bundle. Indirect immunofluorescence study demonstrated that ABP140 was colocalized with both cortical actin patches and cytoplasmic actin cables in intact cells. However, elimination of ABP140 by gene disruption did not show a deleterious effect on cell growth or affect the organization of F-actin. These results indicate that ABP140 is not required for cell growth but may be involved in the reorganization of F-actin in the budding yeast.

We examined mortality from adult T-cell leukemia/lymphoma (ATL/ATLL) and other diseases alleged to be associated with human T-lymphotropic virus type I (HTLV-I) among anti-HTLV-I antibody-positive blood donors in Kyushu, Japan. During 1984-87, a total of 3,991 blood donors aged 40 years or over were followed from the date of donation to the date of death or the end of the study. Crude mortality rates from ATL (with 95 percent confidence intervals) were 68 per 100,000 (13-202) for males and 36 per 100,000 (3-132) for females. The rates were underestimated by approximately 50 percent because of self-selection and short observation periods. Neither death rates from other cancers nor death rates from all cancers were elevated.