ZASP: a new Z-band alternatively spliced PDZ-motif protein.
PDZ motifs are modular protein-protein interaction domains, consisting of 80-120 amino acid residues, whose function appears to be the direction of intracellular proteins to multiprotein complexes. In skeletal muscle, there are a few known PDZ-domain proteins, which include neuronal nitric oxide synthase and syntrophin, both of which are components of the dystrophin complex, and actinin-associated LIM protein, which binds to the spectrin-like repeats of alpha-actinin-2. Here, we report the identification and characterization of a new skeletal muscle protein containing a PDZ domain that binds to the COOH-terminal region of alpha-actinin-2. This novel 31-kD protein is specifically expressed in heart and skeletal muscle. Using antibodies produced to a fragment of the protein, we can show its location in the sarcomere at the level of the Z-band by immunoelectron microscopy. At least two proteins, 32 kD and 78 kD, can be detected by Western blot analysis of both heart and skeletal muscle, suggesting the existence of alternative forms of the protein. In fact, several forms were found that appear to be the result of alternative splicing. The transcript coding for this Z-band alternatively spliced PDZ motif (ZASP) protein maps on chromosome 10q22.3-10q23.2, near the locus for infantile-onset spinocerebellar ataxia.
Faulkner
G
G
International Centre for Genetic Engineering and Biotechnology, I-34012 Trieste, Italy. faulkner@icgeb.treste.it
Pallavicini
A
A
Formentin
E
E
Comelli
A
A
Ievolella
C
C
Trevisan
S
S
Bortoletto
G
G
Scannapieco
P
P
Salamon
M
M
Mouly
V
V
Valle
G
G
Lanfranchi
G
G
D000185:Actinin / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002879:Chromosomes, Human, Pair 10 / Q000235:genetics; D003001:Cloning, Molecular; D005455:Fluorescent Antibody Technique; D006321:Heart / Q000196:embryology; D018398:Homeodomain Proteins; D006801:Humans; D060588:LIM Domain Proteins; D051379:Mice; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009124:Muscle Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure; D009928:Organ Specificity; D011233:Precipitin Tests; D011485:Protein Binding; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D012518:Sarcomeres / Q000378:metabolism* / Q000648:ultrastructure; D015003:Yeasts / Q000235:genetics
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018398:Homeodomain Proteins; C120696:LDB3 protein, human; D060588:LIM Domain Proteins; C485639:Ldb3 protein, mouse; D009124:Muscle Proteins; D012333:RNA, Messenger; D000185:Actinin