Mitochondrial cysteine synthase complex regulates O-acetylserine biosynthesis in plants.

Cysteine synthesis is catalyzed by serine acetyltransferase (SAT) and O-acetylserine (thiol) lyase (OAS-TL) in the cytosol, plastids, and mitochondria of plants. Biochemical analyses of recombinant plant SAT and OAS-TL indicate that the reversible association of the proteins in the cysteine synthase complex (CSC) controls cellular sulfur homeostasis. However, the relevance of CSC formation in each compartment for flux control of cysteine synthesis remains controversial.

Bi-specific aptamers mediating tumor cell lysis.

Antibody-dependent cellular cytotoxicity plays a pivotal role in antibody-based tumor therapies and is based on the recruitment of natural killer cells to antibody-bound tumor cells via binding of the Fcγ receptor III (CD16). Here we describe the generation of chimeric DNA aptamers that simultaneously bind to CD16α and c-Met, a receptor that is overexpressed in many tumors. By application of the systematic evolution of ligands by exponential enrichment (SELEX) method, CD16α specific DNA aptamers were isolated that bound with high specificity and affinity (91 pm-195 nm) to their respective recombinant and cellularly expressed target proteins.