Product details
Synonyms = Tripartite motif containing 72, MG53
Antibody type = Recombinant Rabbit monoclonal / IgG
Clone = HMV313
Positive control = Skeletal muscle: A strong membranous and cytoplasmic TRIM72 immunostaining should be seen in skeletal muscle cells.
Negative control = Tonsil: All cell types must completely lack TRIM72 staining.
Cellular localization =Intracellular
Reactivity = Human
Application = Immunohistochemistry
Dilution = 1:100 – 1:200
Intended Use = Research Use Only
Relevance of Antibody
TRIM72 is a marker for skeletal muscle cells.
Biology Behind
Tripartite motif protein 72 (TRIM72) is one out of a family of 80 tripartite motif proteins. It is coded by the TRIM72 gene on chromosome 16p11.2 and consists of four domains: RING domain, B-box domain, coiled-coil domain, and SPRY domain. TRIM72 is predominantly expressed in skeletal muscle. Muscle cell membrane repair is believed to represent its main function but TRIM72 also has roles in calcium homeostasis, muscle contraction, vesicle trafficking, anti-inflammation, reduction of oxidative stress, and regulation of systemic insulin response.
Staining Pattern in Normal Tissues
Images describing the TRIM72 staining pattern in normal tissues obtained by the antibody HMV313 are shown in our “Normal Tissue Gallery”.
| Brain | Cerebrum | Negative. |
| Cerebellum | A weak TRIM72 staining of fibres in the molecular layer may occur. | |
| Endocrine Tissues | Thyroid | Negative. |
| Parathyroid | Negative. | |
| Adrenal gland | Negative. | |
| Pituitary gland | Negative. | |
| Respiratory system | Respiratory epithelium | Negative. |
| Lung | Negative. | |
| Gastrointestinal Tract | Salivary glands | Weak to moderate, primarily cytoplasmic TRIM72 staining of a subset of excretory duct epithelial cells. |
| Esophagus | Negative. | |
| Stomach | Negative. | |
| Duodenum | Negative. | |
| Small intestine | Negative. | |
| Appendix | Negative. | |
| Colon | Negative. | |
| Rectum | Negative. | |
| Liver | Negative. | |
| Gallbladder | Negative. | |
| Pancreas | Negative. | |
| Genitourinary | Kidney | TRIM72 staining of arterioles and small arteries can occur. |
| Urothelium | Negative. | |
| Male genital | Prostate | Negative. |
| Seminal vesicles | Negative. | |
| Testis | Negative. | |
| Epididymis | Negative. | |
| Female genital | Breast | Negative. |
| Uterus, myometrium | Negative. | |
| Uterus, ectocervix | Negative. | |
| Uterus endocervix | Negative. | |
| Uterus, endometrium | Negative. | |
| Fallopian Tube | Negative. | |
| Ovary | Negative. | |
| Placenta early | Negative. | |
| Placenta mature | Negative. | |
| Amnion | Negative. | |
| Chorion | Negative. | |
| Skin | Epidermis | Negative. |
| Sebaceous glands | Negative. | |
| Muscle/connective tissue | Heart muscle | Negative. |
| Skeletal muscle | Strong membranous and cytoplasmic TRIM72 staining of skeletal muscle cells. | |
| Smooth muscle | TRIM72 staining of the walls of vessels can be found in the smooth muscular wall of various organs, especially in the GIT. | |
| Vessel walls | A weak to moderate, predominantly cytoplasmic TRIM72 staining of muscle cells of the walls of small vessels can occur. These include muscular small arteries, arterioles, and perhaps also venous vessels. | |
| Fat | Negative. | |
| Stroma | Negative. | |
| Endothelium | Negative. | |
| Bone marrow/ lymphoid tissue | Bone marrow | Negative. |
| Lymph node | Negative. | |
| Spleen | Negative. | |
| Thymus | Distinct TRIM72 staining of a small subset of epithelial cells some of which are associated with corpuscles of Hassall‘s. | |
| Tonsil | Negative. | |
| Remarks | A weak to moderate cytoplasmic TRIM72 staining of muscle cells of the walls of small vessels can occur in various organs. A limitation of this phenomenon to specific organs/tissues cannot be excluded. |
TRIM72 immunostaining by HMV309 largely predominates in skeletal muscle. This is consistent with the RNA data described in the Human Protein Atlas (Tissue expression TRIM72).
Positive control = Skeletal muscle: A strong membranous and cytoplasmic TRIM72 immunostaining should be seen in skeletal muscle cells.
Negative control = Tonsil: All cell types must completely lack TRIM72 staining.
Staining Pattern in Relevant Tumor Types
TRIM72 immunostaining can be often found in tumor cells with skeletal muscle differentiation. At lower frequency TRIM72 expression also occurs in various other cancer entities.
The TCGA findings on TRIM72 RNA expression in different tumor categories have been summarized in the Human Protein Atlas.
Compatibility of Antibodies
No data available at the moment
Protocol Recommendations
IHC users have different preferences on how the stains should look like. Some prefer high staining intensity of the target stain and even accept some background. Others favor absolute specificity and lighter target stains. Factors that invariably lead to more intense staining include higher concentration of the antibody and visualization tools, longer incubation time, higher temperature during incubation, higher temperature and longer duration of the heat induced epitope retrieval (slide pretreatment). The impact of the pH during slide pretreatment has variable effects and depends on the antibody and the target protein.
All images and data shown here and in our image galleries are obtained by the manual protocol described below. Other protocols resulting in equivalent staining are described as well.
Manual protocol
Freshly cut sections should be used (less than 10 days between cutting and staining). Heat-induced antigen retrieval for 5 minutes in an autoclave at 121°C in pH 7,8 Target Retrieval Solution buffer. Apply HMV309 at a dilution of 1:200 at 37°C for 60 minutes. Visualization of bound antibody by the EnVision Kit (Dako, Agilent) according to the manufacturer’s directions.
Potential Research Applications
- The function of TRIM72 in skeletal muscle is not completely understood.
- The role and significance of TRIM72 expression on non-skeletal muscle cancers is unclear.
Evidence for Antibody Specificity in IHC
In principle, there are two ways how the specificity of antibodies can be documented for immunohistochemistry on formalin fixed tissues. These are: 1. Comparison with a second independent method for target expression measurement across a large number of different tissue types (orthogonal strategy), and 2. Comparison with one or several independent antibodies for the same target and showing that all positive staining results are also seen with other antibodies for the same target (independent antibody strategy).
Orthogonal validation: For the antibody HMV309 specificity is suggested by the good concordance of the immunostaining data with data from three independent RNA screening studies, including the Human Protein Atlas (HPA) RNA-seq tissue dataset, the FANTOM5 project, and the Genotype-Tissue Expression (GTEx) project, which are all summarized in the Human Protein Atlas (Tissue expression TRIM72). TRIM72 RNA expression was only described in skeletal muscle, the tissue type with – by far – the strongest TRIM72 immunostaining by HMV309. TRIM72 immunostaining by HMV309 was, however, also seen in cell types for which RNA expression has not been previously documented. These cell types include a small subset of epithelial cells of the thymus, muscle cells of the walls of small vessels, a subset of epithelial cells of excretory ducts of salivary glands, and fibres in the molecular layer of the cerebellum.
Comparison of antibodies: True expression of TRIM72 in most cell types (epithelial cells of the thymus, muscle cells of small vessels, epithelial cells of excretory ducts of salivary glands) found to be TRIM72 positive by HMV309 was corroborated by identical staining’s obtained by another commercially available independent antibody (termed “validation antibody”). The only staining by HMV309 which was not confirmed by the “validation antibody” is a weak staining of intracranial nerve fibres in the molecular layer of the cerebellum. This staining is thus considered a potential cross-reactivity of HMV309. This is not completely certain, however, since the staining of the validation antibody was – in general – considerably weaker as seen for HMV309 and the cerebral staining was rather weak. That the “RNA negative” cell types with IHC positivity for HMV309 were not detected in RNA analyses may be due to the small percentage of the positive cells as compared to the respective organs. Independence of the validation antibody is supported by cross-reactivity with smooth muscles of various organs and a cytoplasmic staining of many tissues.
