The LIM domain protein UNC-95 is required for the assembly of muscle attachment structures and is regulated by the RING finger protein RNF-5 in C. elegans.
Here, we describe a new muscle LIM domain protein, UNC-95, and identify it as a novel target for the RING finger protein RNF-5 in the Caenorhabditis elegans body wall muscle. unc-95(su33) animals have disorganized muscle actin and myosin-containing filaments as a result of a failure to assemble normal muscle adhesion structures. UNC-95 is active downstream of PAT-3/beta-integrin in the assembly pathways of the muscle dense body and M-line attachments, and upstream of DEB-1/vinculin in the dense body assembly pathway. The translational UNC-95::GFP fusion construct is expressed in dense bodies, M-lines, and muscle-muscle cell boundaries as well as in muscle cell bodies. UNC-95 is partially colocalized with RNF-5 in muscle dense bodies and its expression and localization are regulated by RNF-5. rnf-5(RNAi) or a RING domain deleted mutant, rnf-5(tm794), exhibit structural defects of the muscle attachment sites. Together, our data demonstrate that UNC-95 constitutes an essential component of muscle adhesion sites that is regulated by RNF-5.
Broday
Limor
L
Ruttenberg Cancer Center, Mount Sinai School of Medicine, Box 1130, New York, NY 10029, USA.
Kolotuev
Irina
I
Didier
Christine
C
Bhoumik
Anindita
A
Podbilewicz
Benjamin
B
Ronai
Ze'ev
Z
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009132:Muscles / Q000502:physiology; D014176:Protein Biosynthesis; D016372:RNA, Antisense / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D016372:RNA, Antisense; D034741:RNA, Small Interfering; C489653:RNF-5 protein, C elegans; D011993:Recombinant Fusion Proteins; C489652:Unc-95 protein, C elegans