cDNA cloning and nucleotide sequence of rat muscle-specific enolase (ββ enolase)

AbstractThe nucleotide sequence of rat muscle-specific enolase cDNA was determined by sequencing three cDNA clones encoding this enolase isozyme. The nearly full-length cDNA consists of 13-bp 5′- and 84-bp 3′-noncoding regions and a poly(A) tail in addition to a 1302-bp coding region encoding a polypeptide composed of 434 amino acid residues. The deduced primary structure of this enolase isozyme is about 80% similar to those determined previously for rat neuron-specific and non-neuronal enolase isozymes. Southern blot analysis suggested strongly the existence of a single copy of the muscle-specific enolase gene per haploid genome. The mRNA for this enolase isozyme was detected in rat skeletal muscle on day 1 after birth and its level increased rapidly during 10–30 days after birth without any change in its size (1500 bases)

Role of the Carboxy-Terminal Region of the GluRε2 Subunit in Synaptic Localization of the NMDA Receptor Channel

AbstractThe synaptic localization of the N-methyl-D-aspartate (NMDA) type glutamate receptor (GluR) channel is a prerequisite for synaptic plasticity in the brain. We generated mutant mice carrying the carboxy-terminal truncated GluRε2 subunit of the NMDA receptor channel. The mutant mice died neonatally and failed to form barrelette structures in the brainstem. The mutation greatly decreased the NMDA receptor–mediated component of hippocampal excitatory postsynaptic potentials and punctate immunofluorescent labelings of GluRε2 protein in the neuropil regions, while GluRε2 protein expression was comparable. Immunostaining of cultured cerebral neurons showed the reduced punctate staining of the truncated GluRε2 protein at synapses. These results suggest that the carboxy-terminal region of the GluRε2 subunit is important for efficient clustering and synaptic localization of the NMDA receptor channel