Tag Content
UniProt Accession
Theoretical PI
Molecular Weight
42302 Da  
Genbank Nucleotide ID
Genbank Protein ID
Gene Name
Gene Synonyms/Alias
Protein Name
Calcium-binding and spermatid-specific protein 1 
Protein Synonyms/Alias
Mus musculus (Mouse) 
NCBI Taxonomy ID
Chromosome Location
View in Ensembl genome browser  
Function in Stage
Function in Cell Type
Probability (GAS) of Function in Spermatogenesis
The probability was calculated by GAS algorithm, ranging from 0 to 1. The closer it is to 1, the more possibly it functions in spermatogenesis.
Temporarily unavailable 
Abstract of related literatures
1. This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development. PMID: [16141072] 

2. The National Institutes of Health's Mammalian Gene Collection (MGC) project was designed to generate and sequence a publicly accessible cDNA resource containing a complete open reading frame (ORF) for every human and mouse gene. The project initially used a random strategy to select clones from a large number of cDNA libraries from diverse tissues. Candidate clones were chosen based on 5'-EST sequences, and then fully sequenced to high accuracy and analyzed by algorithms developed for this project. Currently, more than 11,000 human and 10,000 mouse genes are represented in MGC by at least one clone with a full ORF. The random selection approach is now reaching a saturation point, and a transition to protocols targeted at the missing transcripts is now required to complete the mouse and human collections. Comparison of the sequence of the MGC clones to reference genome sequences reveals that most cDNA clones are of very high sequence quality, although it is likely that some cDNAs may carry missense variants as a consequence of experimental artifact, such as PCR, cloning, or reverse transcriptase errors. Recently, a rat cDNA component was added to the project, and ongoing frog (Xenopus) and zebrafish (Danio) cDNA projects were expanded to take advantage of the high-throughput MGC pipeline. PMID: [15489334] 

3. Single intraperitoneal injection of busulfan at 20 mg/kg body weight to mature male mice induced the deletion of the spermatogenic cells, followed by the restoration of the spermatogenesis by the surviving undifferentiated spermatogonia. The changes of the protein contents in testis during these processes were analyzed by two-dimensional gel electrophoresis in order to identify the proteins expressed at the specific stages of spermatogenesis. An acidic protein that disappeared and recovered in the same time course as spermatids after the busulfan treatment was identified as CABS1 by mass spectrometry. It was found that CABS1 was specifically expressed in the elongate spermatids at steps 13 to 16 in stages I to VIII of the seminiferous epithelium cycle of the mouse, and then it localized to the principal piece of flagellum of the mature sperm in the cauda epididymis. We have found for the first time that CABS1 is a calcium-binding protein that binds calcium during the maturation in the epididymis. PMID: [19208547] 

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Subcellular Location
Cytoplasm (By similarity). Mitochondrion (Bysimilarity). Cell projection, cilium, flagellum. Note=Detected inmitochondria of step 17 to 18 spermatids. Associated with themitochondrial inner membrane in step 18 spermatids (Bysimilarity). 
Tissue Specificity
Detected only in testis. Expressed from stagesX to VIII of the seminiferous epithelial cycle. Expressed fromstep 13 to step 16 of spermatid development (at protein level). 
Gene Ontology
GO IDGO termEvidence
GO:0019861 C:flagellum IDA:UniProtKB.
GO:0005743 C:mitochondrial inner membrane IEA:Compara.
GO:0005509 F:calcium ion binding IDA:UniProtKB.
GO:0007283 P:spermatogenesis IEA:Compara.
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IPR026118;    Ca-bd_spermatid.
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Created Date
Record Type
GAS predicted 
Sequence Annotation
CHAIN         1    391       Calcium-binding and spermatid-specific
                             protein 1.
CONFLICT      8      8       K -> Q (in Ref. 1; BAB30237).
CONFLICT    108    108       S -> V (in Ref. 1; BAB30237).
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Nucleotide Sequence
Length: 1320 bp   Go to nucleotide: FASTA
Protein Sequence
Length: 391 bp   Go to amino acid: FASTA
The verified Protein-Protein interaction information
Gene Symbol Ref Databases
Other Protein-Protein interaction resources
String database  
View Microarray data