Isolation of a cDNA encoding the rat MAP-kinase homolog of human p63mapk.
Using a combination of screening, RACE, and RT-PCR, we have isolated a new rat brain cDNA, we refer to as rMNK2, that showed strong homology to known MAP-kinases. The deduced amino acid sequence of rMNK2 indicated that it is the rat homolog of human p63(mapk), showing 94.5% identity. rMNK2 showed 77% homology with rat ERK3 and its human homolog p97(mapk), and 43% homology with both rat genes rMNK1(ERK1) and ERK2, within the kinase domain. This suggest that rMNK2 and ERK3 belong to a separate subfamily within the rat MAP-kinase multigene family. The most interesting difference lies in subdomain VIII, where this new subfamily contain a SEG/SPR motif instead of the TEY/APE found in the ERK subfamily, the TPY/APE found in the JNK/SAPK subfamily or the TGY/APE found in the p38/RK subfamily. The human homologs of ERK3 and rMNK2 (p97(mapk) and p63(mapk)) also show this significant change. Expression of rMNK2 has been detected in brain and to a lesser extent in lung by reverse transcription/PCR (RT-PCR). In situ hybridization of rat brain slices demonstrated a restricted expression of rMNK2 in the choroid plexus and hippocampus. This is interesting because the human homolog p63(mapk) maps to 18q12-21, a region that might be implicated in manic-depressive illness.
García
J I
JI
Departamento de Bioquímica, Universidad de Navarra, Pamplona, Spain.
Zalba
G
G
Detera-Wadleigh
S D
SD
de Miguel
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000302:isolation & purification; D048049:Extracellular Signal-Regulated MAP Kinases; D006801:Humans; D017403:In Situ Hybridization; D048053:Mitogen-Activated Protein Kinase 6; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D051381:Rats; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; C102548:Mapk4 protein, rat; D048053:Mitogen-Activated Protein Kinase 6; D020928:Mitogen-Activated Protein Kinases