The mouse protein is part of a conserved gene family, with C19orf77 orthologs identified in multiple species, including bowhead whales (59.82% protein identity) . In humans, SMIM24 is a small integral membrane protein with two transmembrane domains, suggesting a role in membrane-associated signaling or transport .
The human SMIM24 protein contains two transmembrane helices (aa 52–99 and 101–130) , which are critical for its localization to cellular membranes. While the mouse homolog’s exact structure is not experimentally validated, sequence homology (44–50% identity with human) implies a similar topology.
Membrane Signaling: Potential involvement in receptor-mediated signaling due to its transmembrane domains.
Cellular Transport: Possible role in ion or molecule transport, though direct evidence is lacking.
Cancer Biology: Human C19orf77 is downregulated in B-cell acute lymphoblastic leukemia (B-ALL), suggesting a tumor suppressor role .
A recombinant CRISPR-Cas9 system targeting 2210404O07Rik is available for gene knockout studies in mice. This AAV vector set includes:
saCas9 (Streptococcus pyogenes Cas9 variant) for efficient gene editing.
Three sgRNA sequences to induce frameshift mutations in exonic regions .
| Vector Feature | Detail |
|---|---|
| Expression System | All-in-one AAV vector (Cas9 + sgRNA) |
| Target Validation | Restriction enzyme digest and sequencing |
| Species Specificity | Mouse |
While siRNA vectors for human C19orf77 are commercially available (e.g., AAV-siRNA pooled vectors ), no mouse-specific siRNA tools are explicitly documented in the provided sources.
Cancer Association:
Orthologous Expression:
Lack of Recombinant Protein Availability:
While human SMIM24 recombinant fragments are available (e.g., aa 52–99 and 101–130) , no commercial recombinant mouse protein is documented. This limits direct biochemical studies.
Functional Validation: Further research is needed to confirm the mouse protein’s role in membrane signaling, transport, or disease.
The Mouse Transmembrane protein C19orf77 homolog is encoded by the gene 2210404O07Rik (NCBI Gene ID: 72273, Accession Number: NM_001099917.1). It is classified as a transmembrane protein homologous to the human C19orf77 protein, also known as transmembrane protein HSPC323 homolog . The protein contains hydrophobic domains spanning cellular membranes, with portions extending into both cytoplasmic and extracellular spaces. Experimental characterization using hydropathy analyses, protease protection assays, and structural studies would be necessary to determine the exact number and arrangement of transmembrane domains.
For effective subcellular localization studies, employ a multi-method approach:
Confocal immunofluorescence microscopy using validated antibodies against 2210404O07Rik combined with organelle markers (ER, Golgi, plasma membrane)
Cell fractionation followed by Western blot analysis to quantify protein distribution between membrane fractions
Live-cell imaging using CRISPR knock-in of fluorescent tags (GFP, mCherry) at the C-terminus of endogenous 2210404O07Rik
Super-resolution microscopy (STORM, PALM) for high-precision localization within membrane microdomains
Electron microscopy with immunogold labeling for ultrastructural localization
When optimizing immunofluorescence protocols, test multiple fixation methods (4% paraformaldehyde, methanol, glutaraldehyde) as transmembrane proteins often require specific conditions for epitope preservation and accessibility.
For CRISPR-based functional studies of 2210404O07Rik, the All-in-one AAV vector system with saCas9 offers several methodological advantages . This system uses Staphylococcus aureus Cas9 (smaller than Streptococcus pyogenes Cas9) making it suitable for AAV packaging.
Implementation protocol:
Select vector: pAAV-PGK-saCas9-U6-sgRNAsa-hGH-amp with three sgRNA targets designed for exonic regions of 2210404O07Rik
Validate sgRNA efficiency in cell lines using T7 Endonuclease I assay before in vivo application
Deliver AAV particles at optimal MOI (typically 100-1000 viral particles per cell)
Confirm knockout efficiency by:
Genomic DNA sequencing across target sites
RT-qPCR to verify mRNA reduction
Western blot to confirm protein elimination
Perform clonal selection to establish homogeneous knockout cell lines
Conduct rescue experiments by reintroducing wild-type 2210404O07Rik to confirm phenotype specificity
The selection of viral vector significantly impacts experimental outcomes when manipulating 2210404O07Rik:
For most 2210404O07Rik functional studies, AAV vectors offer an optimal balance of efficiency, long-term expression, and safety profile, particularly when delivering CRISPR components.
To accurately differentiate and quantify potential splice variants of 2210404O07Rik:
Design isoform-specific RT-qPCR assays:
Create primers spanning unique exon-exon junctions
Optimize annealing temperatures using gradient PCR
Validate specificity using synthetic templates of each isoform
Employ RNA-seq analysis with specialized computational pipelines:
Use algorithms specifically designed for isoform quantification (RSEM, Salmon)
Apply sufficient sequencing depth (>30M reads per sample)
Validate novel junctions with targeted RT-PCR
Perform long-read sequencing (PacBio or Oxford Nanopore):
Sequence full-length transcripts to unambiguously identify isoforms
Use targeted approaches like PCR-cDNA sequencing for focused analysis
Validate protein isoforms:
Develop isoform-specific antibodies targeting unique regions
Use Western blotting with appropriate controls for each variant
Consider immunoprecipitation followed by mass spectrometry for unbiased detection
For comprehensive epigenetic analysis of 2210404O07Rik regulation:
DNA methylation profiling:
Apply Illumina's Infinium Methylation EPIC BeadChip assay to quantify methylation at relevant CpG sites
Calculate beta values as the ratio of methylated signals to total signals (range: 0-1)
Identify significant methylation differences using statistical thresholds:
Correct for cell-type heterogeneity using computational algorithms like EpiDISH
Histone modification analysis:
Perform ChIP-seq targeting key modifications:
H3K4me3 (active promoters)
H3K27ac (active enhancers)
H3K27me3 (repressive marks)
Create enhancer-promoter interaction maps using Hi-C or ChIA-PET
Integrate with expression data to correlate chromatin state with transcription
Transcription factor binding analysis:
To systematically evaluate 2210404O07Rik's involvement in T-cell development:
Establish baseline expression profile:
In vitro developmental assays:
Employ the OP9-DL1 co-culture system for controlled T-cell differentiation studies :
Isolate CD34+ hematopoietic stem cells (HSCs)
Culture on OP9 stromal cells expressing Delta-like 1 ligand
Monitor progression through T-cell developmental stages
Assess effects of 2210404O07Rik manipulation on differentiation kinetics
Perform CRISPR knockout of 2210404O07Rik in HSCs using the AAV-saCas9 system
Evaluate impacts on:
In vivo developmental studies:
To investigate potential NOTCH-2210404O07Rik interactions in T-cell development:
Expression correlation analysis:
Genetic interaction studies:
Molecular interaction analysis:
Investigate physical interactions:
Co-immunoprecipitation of 2210404O07Rik with NOTCH receptors or pathway components
Proximity ligation assay for in situ interaction detection
Domain mapping to identify specific interaction interfaces
Signaling pathway analysis:
For optimized stable expression of potentially challenging transmembrane proteins:
Vector design considerations:
Use expression vectors with moderate promoters (CMV, EF1α) to avoid toxicity from overexpression
Include purification tags positioned to avoid disrupting transmembrane domains
Consider inducible expression systems (Tet-On/Off) to control expression levels
Cell line selection optimization:
Test multiple cell backgrounds (HEK293, CHO, Jurkat)
For T-cell studies, compare expression in immature (Jurkat) versus mature (primary T-cells) lineages
Evaluate growth characteristics and expression stability over multiple passages
Transfection/transduction protocol refinement:
For lentiviral delivery:
Optimize vector concentration (300-1000 ng p24/mL)
Test polybrene (2-10 μg/mL) to enhance membrane fusion
Use spinoculation (800-1200 g for 90 minutes) to increase efficiency
For AAV delivery:
Calculate optimal vector genome copies (1000-10000 GC/cell)
Evaluate different AAV serotypes for target cell tropism
Selection strategy:
Implement dual selection methods (antibiotic resistance plus fluorescent marker)
Perform single-cell sorting to establish clonal populations
Validate expression using multiple methods (Western blot, flow cytometry, RT-qPCR)
To enhance detection sensitivity for potentially low-abundance transmembrane proteins:
Tissue preparation optimization:
Test multiple fixation protocols:
Paraformaldehyde (2-4%) for morphology preservation
Methanol for certain transmembrane epitopes
Combined protocols with gentler fixatives like DSP (dithiobis-succinimidyl propionate)
Optimize antigen retrieval:
Test heat-induced (citrate buffer, pH 6.0; EDTA buffer, pH 9.0)
Enzymatic methods (proteinase K, trypsin)
Combination approaches for maximum epitope exposure
Advanced detection technologies:
Apply signal amplification methods:
Tyramide signal amplification (increases sensitivity 10-50 fold)
Quantum dot secondary antibodies for improved signal-to-noise ratio
RNAscope for highly sensitive mRNA detection when protein detection is challenging
Validation controls:
Use tissues from 2210404O07Rik knockout models as negative controls
Include tissues with confirmed high expression as positive controls
Employ multiple antibodies targeting different epitopes for confirmation
Sample enrichment strategies:
Perform membrane fraction isolation before Western blot analysis
Use immunoprecipitation to concentrate target protein
Consider proximity labeling approaches (BioID, APEX) for associated protein complex isolation