Human Beta-Defensin 2 and 3 Inhibit HIV-1 Replication in Macrophages.

Human beta-defensins (hBDs) are broad-spectrum antimicrobial peptides, secreted by epithelial cells of the skin and mucosae, and astrocytes, which we and others have shown to inhibit HIV-1 in primary CD4 T cells. Although loss of CD4 T cells contributes to mucosal immune dysfunction, macrophages are a major source of persistence and spread of HIV and also contribute to the development of various HIV-associated complications. We hypothesized that, besides T cells, hBDs could protect macrophages from HIV.

Interleukin-27, an anti-HIV-1 cytokine, inhibits replication of hepatitis C virus.

Interleukin (IL)-27 is a member of IL-12 family cytokine. We have previously reported that IL-27 inhibits human immunodeficiency virus type-1 (HIV-1) replication in CD4(+) T cells and monocyte-derived macrophages, even though IL-12 enhances HIV-1 replication in primary CD4(+) T cells. Further study demonstrates that IL-27 induces antiviral genes including RNA-dependent protein kinase, oligoadenylate synthetase, and myxovirus protein in the same manner as interferon (IFN)-alpha.

Saccharomyces cerevisiae Afr1 protein is a protein phosphatase 1/Glc7-targeting subunit that regulates the septin cytoskeleton during mating.

Glc7, the type1 serine/threonine phosphatase in the yeast Saccharomyces cerevisiae, is targeted by auxiliary subunits to numerous locations in the cell, where it regulates a range of physiological pathways. We show here that the accumulation of Glc7 at mating projections requires Afr1, a protein required for the formation of normal projections. AFR1-null mutants fail to target Glc7 to projections, and an Afr1 variant specifically defective in binding to Glc7 [Afr1(V546A F548A)] forms aberrant projections.

Protein phosphatase type 1 directs chitin synthesis at the bud neck in Saccharomyces cerevisiae.

Yeast chitin synthase III (CSIII) is targeted to the bud neck, where it is thought to be tethered by the septin-associated protein Bni4. Bni4 also associates with the yeast protein phosphatase (PP1) catalytic subunit, Glc7. To identify regions of Bni4 necessary for its targeting functions, we created a collection of 23 deletion mutants throughout the length of Bni4.

Ypi1, a positive regulator of nuclear protein phosphatase type 1 activity in Saccharomyces cerevisiae.

The catalytic subunit of protein phosphatase type 1 (PP1) has an essential role in mitosis, acting in opposition to the Ipl1/Aurora B protein kinase to ensure proper kinetochore-microtubule interactions. However, the regulatory subunit(s) that completes the PP1 holoenzyme that functions in this capacity is not known. We show here that the budding yeast Ypi1 protein is a nuclear protein that functions with PP1 (Glc7) in this mitotic role.