Phosphorylation of synaptic vesicle protein 2A at Thr84 by casein kinase 1 family kinases controls the specific retrieval of synaptotagmin-1.

Synaptic vesicle protein 2A (SV2A) is a ubiquitous component of synaptic vesicles (SVs). It has roles in both SV trafficking and neurotransmitter release. We demonstrate that Casein kinase 1 family members, including isoforms of Tau-tubulin protein kinases (TTBK1 and TTBK2), phosphorylate human SV2A at two constellations of residues, namely Cluster-1 (Ser42, Ser45, and Ser47) and Cluster-2 (Ser80, Ser81, and Thr84).

Proteomic identification of novel secreted antibacterial toxins of the Serratia marcescens type VI secretion system.

It has recently become apparent that the Type VI secretion system (T6SS) is a complex macromolecular machine used by many bacterial species to inject effector proteins into eukaryotic or bacterial cells, with significant implications for virulence and interbacterial competition. "Antibacterial" T6SSs, such as the one elaborated by the opportunistic human pathogen, Serratia marcescens, confer on the secreting bacterium the ability to rapidly and efficiently kill rival bacteria. Identification of secreted substrates of the T6SS is critical to understanding its role and ability to kill other cells, but only a limited number of effectors have been reported so far.

Processing by rhomboid protease is required for Providencia stuartii TatA to interact with TatC and to form functional homo-oligomeric complexes.

The twin arginine transport (Tat) system transports folded proteins across the prokaryotic cytoplasmic membrane and the plant thylakoid membrane. In Escherichia coli three membrane proteins, TatA, TatB and TatC, are essential components of the machinery. TatA from Providencia stuartii is homologous to E.

Escherichia coli TatA and TatB proteins have N-out, C-in topology in intact cells.

The twin arginine protein transport (Tat) system translocates folded proteins across the cytoplasmic membrane of prokaryotes and the thylakoid membrane of chloroplasts. In Escherichia coli, TatA, TatB, and TatC are essential components of the machinery. A complex of TatB and TatC acts as the substrate receptor, whereas TatA is proposed to form the Tat transport channel.

The opportunistic pathogen Serratia marcescens utilizes type VI secretion to target bacterial competitors.

The type VI secretion system (T6SS) is the most recently described and least understood of the protein secretion systems of Gram-negative bacteria. It is widely distributed and has been implicated in the virulence of various pathogens, but its mechanism and exact mode of action remain to be defined. Additionally there have been several very recent reports that some T6SSs can target bacteria rather than eukaryotic cells.