Tag Content
SG ID
SG00000277 
UniProt Accession
Theoretical PI
9.27  
Molecular Weight
30182 Da  
Genbank Nucleotide ID
Genbank Protein ID
Gene Name
spag4 
Gene Synonyms/Alias
giac 
Protein Name
 
Protein Synonyms/Alias
SubName: Giacomo 
Organism
Drosophila melanogaster (Fruit fly) 
NCBI Taxonomy ID
7227 
Chromosome Location
chr:2L;11610510-11611772;-1
View in Ensembl genome browser  
Function in Stage
Function in Cell Type
Description
Temporarily unavailable 
The information of related literatures
1. M. P. Kracklauer, H. M. Wiora, W. J. Deery, X. Chen, B. Bolival, Jr., D. Romanowicz, R. A. Simonette, M. T. Fuller, J. A. Fischer and K. M. Beckingham (2010) The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 123(Pt 16): 2763-72. 

Abstract
Maintaining the proximity of centrosomes to nuclei is important in several cellular contexts, and LINC complexes formed by SUN and KASH proteins are crucial in this process. Here, we characterize the presumed Drosophila ortholog of the mammalian SUN protein, sperm-associated antigen 4 (Spag4, previously named Giacomo), and demonstrate that Spag4 is required for centriole and nuclear attachment during spermatogenesis. Production of spag4 mRNA is limited to the testis, and Spag4 protein shows a dynamic pattern of association with the germline nuclei, including a concentration of protein at the site of attachment of the single spermatid centriole. In the absence of Spag4, nuclei and centrioles or basal bodies (BBs) dissociate from each other after meiosis. This role of Spag4 in centriolar attachment does not involve either of the two KASH proteins of the Drosophila genome (Klarsicht and MSP-300), but does require the coiled-coil protein Yuri Gagarin. Yuri shows an identical pattern of localization at the nuclear surface to Spag4 during spermatogenesis, and epistasis studies show that the activities of Yuri and dynein-dynactin are downstream of spag4 in this centriole attachment pathway. The later defects in spermatogenesis seen for yuri and spag4 mutants are similar, suggesting they could be secondary to initial disruption of events at the nuclear surface. PMID: [20647369] 

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Figures for illustrating the function of this protein/gene
Ref: M. P. Kracklauer, H. M. Wiora, W. J. Deery, X. Chen, B. Bolival, Jr., D. Romanowicz, R. A. Simonette, M. T. Fuller, J. A. Fischer and K. M. Beckingham (2010) The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 123(Pt 16): 2763-72. PMID: [20647369]
Ref: M. P. Kracklauer, H. M. Wiora, W. J. Deery, X. Chen, B. Bolival, Jr., D. Romanowicz, R. A. Simonette, M. T. Fuller, J. A. Fischer and K. M. Beckingham (2010) The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 123(Pt 16): 2763-72. PMID: [20647369]
Ref: M. P. Kracklauer, H. M. Wiora, W. J. Deery, X. Chen, B. Bolival, Jr., D. Romanowicz, R. A. Simonette, M. T. Fuller, J. A. Fischer and K. M. Beckingham (2010) The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 123(Pt 16): 2763-72. PMID: [20647369]
Ref: M. P. Kracklauer, H. M. Wiora, W. J. Deery, X. Chen, B. Bolival, Jr., D. Romanowicz, R. A. Simonette, M. T. Fuller, J. A. Fischer and K. M. Beckingham (2010) The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 123(Pt 16): 2763-72. PMID: [20647369]
Ref: M. P. Kracklauer, H. M. Wiora, W. J. Deery, X. Chen, B. Bolival, Jr., D. Romanowicz, R. A. Simonette, M. T. Fuller, J. A. Fischer and K. M. Beckingham (2010) The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 123(Pt 16): 2763-72. PMID: [20647369]
Ref: M. P. Kracklauer, H. M. Wiora, W. J. Deery, X. Chen, B. Bolival, Jr., D. Romanowicz, R. A. Simonette, M. T. Fuller, J. A. Fischer and K. M. Beckingham (2010) The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 123(Pt 16): 2763-72. PMID: [20647369]
Function
 
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Subcellular Location
 
Tissue Specificity
 
Gene Ontology
GO IDGO termEvidence
GO:0007283 P:spermatogenesis IMP:FlyBase.
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Interpro
IPR012919;    Sad1_UNC_C.
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Pfam
PF07738;    Sad1_UNC;    1.
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SMART
PROSITE
PS51469;    SUN;    1.
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PRINTS
Created Date
18-Oct-2012 
Record Type
Experiment identified 
Protein sequence Annotation
Nucleotide Sequence
Length: bp   Go to nucleotide: FASTA
Protein Sequence
Length: 273 bp   Go to amino acid: FASTA
The verified Protein-Protein interaction information
UniProt
Gene Symbol Ref Databases
Other Protein-Protein interaction resources
String database  
View Microarray data
Temporarily unavailable 
Comments