Plectin is a versatile intermediate filament (IF)-bound cytolinker protein with a variety of differentially spliced isoforms accounting for its multiple functions. One particular isoform, plectin 1b (P1b), remains associated with mitochondria after biochemical fractionation of fibroblasts and cells expressing exogenous P1b. Here, we determined that P1b is inserted into the outer mitochondrial m...

The mouse NKR-P1 family includes at least three genes: NKR-P1A, -B, -C. Neither surface expression nor function of the NKR-P1B gene product has previously been shown. Here, we demonstrate that the SJL/J allele of the NKR-P1B gene product is expressed on SJL/J NK cells, and is recognized by PK136 mAb. Interestingly, the same mAb does not recognize the NKR-P1B gene product of C57BL/6. We have als...

NKR-P1B is a homodimeric type II transmembrane C-type lectinlike receptor that inhibits natural killer (NK) cell function upon interaction with its cognate C-type lectin-related ligand, Clr-b. The NKR-P1B:Clr-b interaction represents a major histocompatibility complex class I (MHC-I)-independent missing-self recognition system that monitors cellular Clr-b levels. We have generated NKR-P1B(B6)-d...

NK1.1 alloantigen expression can be used to define NK cells in certain mouse strains, such as B6 (NKR-P1C) and SJL (NKR-P1B). However, BALB/c NK cells do not react with the anti-NK1.1 mAb, PK136. To investigate the NK1.1(-) phenotype of BALB/c NK cells, we have undertaken NK1.1 epitope mapping and genomic analysis of the BALB/c Nkrp1 region. Bacterial artificial chromosome library analysis reve...

Phytoremediation refers to the use of plants for extraction and detoxification of pollutants, providing a new and powerful weapon against a polluted environment. In some plants, such as Thlaspi spp, heavy metal ATPases are involved in overall metal ion homeostasis and hyperaccumulation. P1B-ATPases pump a wide range of cations, especially heavy metals, across membranes against their electrochem...

The P1B-ATPases are a ubiquitous family of metal transporters. These transporters are classified into subfamilies on the basis of substrate specificity, which is conferred by conserved amino acids in the last three transmembrane domains. Five subfamilies have been identified to date, and representative members of four (P1B-1 to P1B-4) have been studied. The fifth family (P1B-5), of which some m...

The P1 protein of viruses of the family Potyviridae is a serine proteinase, which is highly variable in length and sequence, and its role in the virus infection cycle is not clear. One of the proposed activities of P1 is to assist HCPro, the product that viruses of the genus Potyvirus use to counteract antiviral defense mediated by RNA silencing. Indeed, an HCPro-coding region is present in all...

The RNA silencing pathway mediated by small interfering RNAs (siRNAs) plays an important antiviral role in eukaryotes. To counteract this defense barrier, a large number of plant viruses express proteins with RNA silencing suppression activity. Recently, it was reported that the ipomovirus Cucumber vein yellowing virus (CVYV), which lacks the typical silencing suppressor of members of the famil...

The mouse NK1.1 Ag originally defined as NK cell receptor (NKR)-P1C (CD161) mediates NK cell activation. Here, we show that another member of the mouse CD161 family, NKR-P1B, represents a novel NK1.1 Ag. In contrast to NKR-P1C, which functions as an activating receptor, NKR-P1B inhibits NK cell activation. Association of NKR-P1B with Src homology 2-containing protein tyrosine phosphatase-1 prov...

Detoxification and homeostatic acquisition of metal ions are vital for all living organisms. We have identified PCA1 in yeast Saccharomyces cerevisiae as an overexpression suppressor of copper toxicity. PCA1 possesses signatures of a P1B-type heavy metal-transporting ATPase that is widely distributed from bacteria to humans. Copper resistance conferred by PCA1 is not dependent on catalytic acti...