Escherichia coli has three major K(+) uptake systems, Trk, Kup, and Kdp, which have been studied extensively at near neutral pH. However, the function of these transporters under acidic conditions is not well understood, although growth and survival under acidic conditions are important for bacterial pathogenesis. In this study, we examined the expression and activity of Kdp under acidic condit...

The genome of D. radiodurans harbors genes for structural and regulatory proteins of Kdp ATPase, in an operon pattern, on Mega plasmid 1. Organization of its two-component regulatory genes is unique. Here we demonstrate that both, the structural as well as regulatory components of the kdp operon of D. radiodurans are expressed quickly as the cells experience potassium limitation but are not exp...

Kdp, an inducible high-affinity K+ transporter in Escherichia coli, is encoded by genes of the kdpABC operon, and its expression is regulated by the products of kdpD and kdpE. Loss of cell turgor has been proposed to be the signal which induces kdp expression (L. A. Laimins, D. B. Rhoads, and W. Epstein, Proc. Natl. Acad. Sci. USA 78:464-468, 1981). We reexamined kdp expression during steady-st...

Transcription of the K(+) transport operon kdp in Escherichia coli is induced during K(+)-limited growth by the action of a dual-component phosphorelay regulatory system comprised of a sensor kinase (integral membrane protein), KdpD, and a DNA-binding response regulator (cytoplasmic protein), KdpE. In this study, we screened for new dke (named dke for decreased kdp expression) mutations (in loc...

Photoautotrophic bacteria have developed mechanisms to maintain K(+) homeostasis under conditions of changing ionic concentrations in the environment. Synechocystis sp. strain PCC 6803 contains genes encoding a well-characterized Ktr-type K(+) uptake transporter (Ktr) and a putative ATP-dependent transporter specific for K(+) (Kdp). The contributions of each of these K(+) transport systems to c...

The Komeda diabetes-prone (KDP) rat is a spontaneous animal model of human autoimmune type 1 diabetes. By positional cloning of the non-MHC major susceptibility locus lddm/kdp1, we recently identified a nonsense mutation in Cblb and also found that lymphocytes of KDP rats infiltrate into various tissues, indicating autoimmunity. The maintenance and production of KDP rats has been a critical pro...

The kdpFABC operon of Escherichia coli encodes the four protein subunits of the Kdp K+ transport system. Kdp is expressed when growth is limited by the availability of K+. Expression of Kdp is dependent on the products of the adjacent kdpDE operon, which encodes a pair of two-component regulators. Studies with kdp-lac fusions led to the suggestion that change in turgor pressure acts as the sign...

We analyse the electromagnetic coupling in the Kemmer-Duffin-Petiau (KDP) equation. Since the KDP–equation which describes spin-0 and spin-1 bosons is of Dirac-type, we examine some analogies and differences from the Dirac equation. The main difference to the Dirac equation is that the KDP equation contains redundant components. We will show that as a result certain interaction terms in the Ham...

Klarsicht, ANC-1 and Syne homology (KASH) proteins localize to the outer nuclear membrane where they connect the nucleus to the cytoskeleton. KASH proteins interact with Sad1-UNC-84 (SUN) proteins to transfer forces across the nuclear envelope to position nuclei or move chromosomes. A new KASH protein, KDP-1, was identified in a membrane yeast two-hybrid screen of a Caenorhabditis elegans libra...

The representation of deep convection in general circulation models is in part informed by cloud-resolving models (CRMs) that function at higher spatial and temporal resolution; however, recent studies have shown that CRMs often fail at capturing the details of deep convection updrafts. With the goal of providing constraint on CRM simulation of deep convection updrafts, ground-based remote-sens...