Mitochondria import many hundreds of different proteins that are encoded by nuclear genes These proteins are targeted to the mitochondria, translocated through the mitochondrial membranes, and sorted to the different mitochondrial subcompartments Separate translocases in the mitochondrial outer membrane (TOM complex) and in the inner membrane (TIM complex) facilitate recognition of preproteins and transport across the two membranes Factors in the cytosol assist in targeting of preproteins Protein components in the matrix partake in energetically driving translocation in a reaction that depends on the membrane potential and matrix-ATP Molecular chaperones in the matrix exert multiple functions in translocation, sorting, folding, and assembly of newly imported proteins

Protein import into mitochondria.

Intricate regulation of tyrosine hydroxylase activity and gene expression

Background There is no practical and reliable premortem test for Creutzfeldt–Jakob disease and the related transmissible spongiform encephalopathies. Two proteins, designated 130 and 131, which have been detected in low concentrations in cerebrospinal fluid from patients with Creutzfeldt–Jakob disease, appear to be sensitive and specific markers for the disease. Attempts to identify these proteins, however, have been unsuccessful. We hypothesized that they may be present in the normal brain. Methods We detected proteins 130 and 131 in normal human brain, partially sequenced their amino acids, and found that they matched the brain protein known as 14-3-3. We then developed a simple, rapid immunoassay for this protein and tested it in cerebrospinal fluid samples from 71 humans and 30 animals with spongiform encephalopathies and in control samples from 186 humans and 94 animals. Results The immunoassay detected the 14-3-3 protein in cerebrospinal fluid from 68 of the 71 patients with Creutzfeldt–Jakob diseas...

The 14-3-3 brain protein in cerebrospinal fluid as a marker for transmissible spongiform encephalopathies.

The ins and outs of Raf kinases.

P-type ATPases form a large superfamily of cation and lipid pumps. They are remarkably simple with only a single catalytic subunit and carry out large domain motions during transport. The atomic structure of P-type ATPases in different conformations, together with ample mutagenesis evidence, has provided detailed insights into the pumping mechanism by these biological nanomachines. Phylogenetically, P-type ATPases are divided into five subfamilies, P1–P5. These subfamilies differ with respect to transported ligands and the way they are regulated.

G. Rosenfeld

Papers

14-3-3 proteins: a highly conserved, widespread family of eukaryotic proteins.