The paralemmin protein family: identification of paralemmin-2, an isoform differentially spliced to AKAP2/AKAP-KL, and of palmdelphin, a more distant cytosolic relative.
Paralemmin is a protein implicated in plasma membrane dynamics. Here we describe the identification of two new paralemmin-related proteins. A partial paralemmin homolog, palmdelphin, is predominantly cytosolic, unlike paralemmin which is lipid-anchored to the plasma membrane through a C-terminal CaaX motif. We have mapped the mouse palmdelphin gene to distal chromosome 3 between Amy2 and Abcd3, in a region homologous to human chromosome 1p22-p21 where the human palmdelphin gene is located. We have also identified a second paralemmin isoform, paralemmin-2. It is expressed from a gene on human chromosome 9q31-q33 which ends only 33 kb upstream of the gene encoding the protein kinase A-binding protein,AKAP2/AKAP-KL. The closely adjacent paralemmin-2 and AKAP2 genes are functionally linked in a very unusual manner. Chimeric mRNAs are expressed, apparently by RNA readthrough and differential splicing, that encode natural fusion proteins in which either the N-terminal coiled-coil region or nearly the complete sequence of paralemmin-2 except its C-terminal CaaX motif is fused to AKAP2/AKAP-KL. The N-terminal coiled-coil region is conserved in paralemmin-1, paralemmin-2/AKAP2, palmdelphin and a fourth, uncharacterized gene, suggesting that it is a modular functional domain.
Hu
B
B
Institut für Physiologische Chemie, Ruhr-Universität Bochum, Universitätsstrasse 150, Bochum, D-44780, Germany.
Copeland
N G
NG
Gilbert
D J
DJ
Jenkins
N A
NA
Kilimann
M W
MW
D054758:A Kinase Anchor Proteins; D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D002645:Chickens; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D003600:Cytosol / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D009928:Organ Specificity; D010750:Phosphoproteins; D020161:Physical Chromosome Mapping; D014176:Protein Biosynthesis; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D009626:Terminology as Topic
D054758:A Kinase Anchor Proteins; C484688:AKAP2 protein, human; D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018076:DNA, Complementary; D008565:Membrane Proteins; C113392:PALM protein, human; C111169:Pakap protein, mouse; C512641:Palm protein, mouse; C434049:Palm2-AKAP2 fusion protein, human; C434124:Palmd protein, mouse; D010750:Phosphoproteins; D020033:Protein Isoforms; D011506:Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins