Focal point technology: Controlling treatment depth and pattern of skin injury by a novel highly focused laser.

Background: Selective photothermolysis has limitations in efficacy and safety for dermal targets. We describe a novel concept using scanned focused laser microbeams for precise control of dermal depth and pattern of injury, using a 1550 nm laser that generates an array of conical thermal zones while minimizing injury to the epidermis.

Objective: To characterize the conical thermal zones in vivo and determine safe starting parameters to transition to a second phase to explore potential clinical indications.

Heterologously secreted MbxA from Moraxella bovis induces a membrane blebbing response of the human host cell.

Many proteins of the Repeats in Toxins (RTX) protein family are toxins of Gram-negative pathogens including hemolysin A (HlyA) of uropathogenic E. coli. RTX proteins are secreted via Type I secretion systems (T1SS) and adopt their native conformation in the Ca-rich extracellular environment.

Identity Determinants of the Translocation Signal for a Type 1 Secretion System.

The toxin hemolysin A was first identified in uropathogenic strains and shown to be secreted in a one-step mechanism by a dedicated secretion machinery. This machinery, which belongs to the Type I secretion system family of the Gram-negative bacteria, is composed of the outer membrane protein TolC, the membrane fusion protein HlyD and the ABC transporter HlyB. The N-terminal domain of HlyA represents the toxin which is followed by a RTX (Repeats in Toxins) domain harboring nonapeptide repeat sequences and the secretion signal at the extreme C-terminus.

Type I Secretion Systems-One Mechanism for All?

Type I secretion systems (T1SS) are widespread in Gram-negative bacteria, especially in pathogenic bacteria, and they secrete adhesins, iron-scavenger proteins, lipases, proteases, or pore-forming toxins in the unfolded state in one step across two membranes without any periplasmic intermediate into the extracellular space. The substrates of T1SS are in general characterized by a C-terminal secretion sequence and nonapeptide repeats, so-called GG repeats, located N terminal to the secretion sequence. These GG repeats bind Ca ions in the extracellular space, which triggers folding of the entire protein.

Type I secretion system-it takes three and a substrate.

Type I secretion systems are widespread in Gram-negative bacteria and mediate the one-step translocation of a large variety of proteins serving for diverse purposes, including nutrient acquisition or bacterial virulence. Common to most substrates of type I secretion systems is the presence of a C-terminal secretion sequence that is not cleaved during or after translocation. Furthermore, these protein secretion nanomachineries are always composed of an ABC transporter, a membrane fusion protein, both located in the inner bacterial membrane, and a protein of the outer membrane.