IGHG1

Fig1. The typical numbers of functional gene segments are shown. (Harry W Schroeder Jr, 2010)

What is IGHG1 protein?

IGHG1 (immunoglobulin heavy constant gamma 1 (G1m marker)) gene is situated on the long arm of chromosome 14 at locus 14q32. Human IgG consists of four subclasses (1-4) that can be recognised by antigen differences in their heavy chains. Each subclass has different biological and physiochemical properties. The IgG subclass may be preferentially produced in response to different antigens. The Fab fragment (fragment antigen binding) is the antigen region of the IgG molecule. It is composed of one constant and one variable domain of each of the heavy and the light chain. The IGHG1 protein is consisted of 399 amino acids and its molecular mass is approximately 43.9 kDa.

What is the function of IGHG1 protein?

Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen.

IGHG1 Related Signaling Pathway

IGHG1 protein is an immunoglobulin, mainly involved in humoral immune response. When it binds to the antigen, it can activate the complement system, trigger an inflammatory response, and promote the proliferation and differentiation of B cells. In addition, IGHG1 is also involved in the occurrence and development of autoimmune diseases.

In addition to humoral immune response, IGHG1 may also be involved in the regulation of other signaling pathways. For example, it can bind to receptors on the cell surface and activate downstream signaling pathways, thereby affecting biological behaviors such as cell growth, differentiation, and migration. In addition, IGHG1 may also be involved in the regulation of apoptosis, angiogenesis and other processes.

IGHG1 Related Diseases

The abnormality of IGHG1 protein may lead to the occurrence of a variety of immune-related diseases, including chronic inflammation and inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel disease. Allergic diseases such as allergic rhinitis, bronchial asthma and autoimmune diseases.

Bioapplications of IGHG1

IGHG1 protein can be used in biosensors, immunostaining and other medical devices for further clinical treatment or scientific research. Or part of the antibody is used to make monoclonal antibodies to treat certain types of cancer and autoimmune diseases.

Case study 1: Yongmei Jin, 2023

This study researched the exact function of IgG1 heavy chain (IGHG1) on breast cancer (BC) progression. IGHG1 level within BC and paired normal tissues was acquired in Gene Expression Profiling Interactive Analysis dataset. Meanwhile, this work harvested tumor and paired healthy tissues in 42 BC cases. siRNA targeting IGHG1 was transfected into BC cells. SC79 was used to treat the transfected BC cells. CCK-8 assay, clone formation experiment, BrdU assay, Transwell experiment and flow cytometry were carried out to measure the viability, colony formation, proliferation, invasion, and apoptosis of BC cells. Paclitaxel and cisplatin sensitivity of BC cells was evaluated by MTT assay. Real-time quantitative reverse transcription-polymerase chain reaction and Western-blot were performed for measuring mRNA and protein expression.

The overexpressed IGHG1 indicated dismal BC survival. IGHG1 silencing attenuated the viability, invasion, proliferation, epithelial-mesenchymal transition, but enhanced the apoptosis of BC cells. IGHG1 silencing enhanced the paclitaxel and cisplatin sensitivity of BC cells. IGHG1 silencing suppressed the activity of the MEK, AKT, and ERK pathways. AKT agonist partially reversed the inhibition of IGHG1 silencing on BC cell malignant phenotype and resistance to paclitaxel and cisplatin. IGHG1 promotes the malignant development of BC by activating the AKT pathway.

Fig1. Clone formation experiment revealed that IGHG1 silencing markedly reduced T-47D and MDA-MB-231 cell proliferation.

Fig2. IGHG1 silencing reduced the AKT pathway activity at the phosphorylation sites of Thr308 and Ser473 in MDA-MB-231 cells.

Case study 2: Jing Chu, 2019

Increasing evidence indicates that immunoglobulins are important for the regulation of various cancers including prostate cancer (PCa). However, the underlying mechanisms of IgG regulated PCa development remain to be further explored. Here, the researchers demonstrated that IgG1 heavy chain (IGHG1) was increased in tissues from PCa patients. Inhibition of IGHG1 by antibody blocking or genetic knockdown suppressed cell growth and induced cell cycle arrest and ultimate apoptosis. Expression levels of c-Myc were positively correlated with the levels of IGHG1. Furthermore, MEK/ERK/c-Myc pathway lied downstream of IGHG1 in cultured prostate cancer cells. Inhibition of IGHG1 restrained the tumor growth in nude mice and inactivated MEK/ERK/c-Myc pathway both in vitro and in vivo.

Fig3. IGHG1 regulates PCa cell growth via MEK/ERK/c-Myc pathway. The statistical data of p-MEK (comparing to total MEK) and p-ERK (comparing to total ERK) were shown.

Fig4. DU145 cells were injected to nude mice, together with or without IGHG1 genetic silenced or IGHG1 antibody injection.

IGHG1 has several biochemical functions, for example, . Some of the functions are cooperated with other proteins, some of the functions could acted by IGHG1 itself. We selected most functions IGHG1 had, and list some proteins which have the same functions with IGHG1. You can find most of the proteins on our site.

IGHG1 has direct interactions with proteins and molecules. Those interactions were detected by several methods such as yeast two hybrid, co-IP, pull-down and so on. We selected proteins and molecules interacted with IGHG1 here. Most of them are supplied by our site. Hope this information will be useful for your research of IGHG1.