Calcium and integrin-binding protein 1 is a protein that in humans is encoded by the CIB1 gene and is located in Chromosome 15. [5] [6] [7] The protein encoded by this gene is a member of the calcium-binding protein family. The specific function of this protein has not yet been determined; however this protein is known to interact with DNA-dependent protein kinase and may play a role in kinase-phosphatase regulation of DNA end-joining. This protein also interacts with integrin alpha(IIb)beta(3), which may implicate this protein as a regulatory molecule for alpha(IIb)beta(3). [7]
CIB1 is a small protein with a molecular weight of approximately 22 kDa. It has a conserved calcium-binding EF hand domain, which consists of two alpha-helices connected by a loop. [8] [9] CIB1 also has an integrin-binding domain, located near the N-terminus of the protein. In addition, CIB1 has a coiled-coil domain and a C-terminal domain. [8] [10] [11] CIB1 is involved in regulating cell adhesion, migration, and differentiation, as well as other cellular processes. It interacts with integrins, which are transmembrane receptors that play a key role in cell signaling and adhesion to the extracellular matrix. CIB1 has also been shown to regulate other signaling pathways that are important for cell survival and proliferation. [8] Upregulation of CIB1 expression has been observed in several types of cancer, and it has been implicated in cancer development and progression. [8] CIB1 is involved in several cellular processes that are important for cancer progression, including cell adhesion, migration, and invasion. It has been shown to interact with integrins, which are transmembrane receptors that play a key role in these processes. [8] The structure and function of CIB1 make it an important protein in regulating various cellular processes, including those involved in cancer progression, and targeting it may offer potential therapeutic benefits.
CIB1 expression has been observed in several types of cancer, including breast, lung, prostate, ovarian, and pancreatic cancer. In breast cancer, CIB1 expression has been shown to be higher in invasive ductal carcinoma compared to normal breast tissue. [12] High levels of CIB1 expression have also been associated with poor prognosis in breast cancer patients. [12] CIB1 has been implicated in cancer development and progression. In breast cancer, CIB1 has been shown to promote cell proliferation, migration, invasion, and metastasis. [13] CIB1 has also been shown to promote the growth of prostate cancer cells and the invasion of ovarian cancer cells. [13] Targeting CIB1 has been explored as a potential therapeutic strategy for cancer. Small molecule inhibitors of CIB1 have shown promise in preclinical models of breast cancer. Silencing CIB1 expression has also been shown to sensitize cancer cells to chemotherapy and radiation therapy. [14] [13]
CIB1 has been implicated in male fertility, specifically in sperm function and motility. [15] CIB1 expression has been detected in human sperm, and its levels have been correlated with sperm motility. CIB1 has also been shown to be present in the acrosome region of the sperm, which plays a critical role in fertilization. Studies in mice have shown that CIB1 deficiency leads to impaired sperm motility and reduced fertility. [8] [15] Male mice lacking CIB1 exhibited decreased sperm count and decreased sperm motility, resulting in reduced fertility. CIB1 was also found to be required for the proper formation of the sperm tail, which is critical for sperm motility. [8] In addition, CIB1 has been shown to regulate calcium signaling in sperm, which is important for sperm motility and fertilization. CIB1 interacts with the sperm-specific calcium channel CatSper, which is important for regulating intracellular calcium levels in sperm. [8]
Spermatogenesis is the process of producing mature spermatozoa from spermatogonia, the precursor cells in the testes. This process involves several stages, including mitotic division, meiotic division, and differentiation, which results in the production of four haploid sperm cells from one diploid spermatogonium. CIB1 has been shown to play a critical role in spermatogenesis by regulating the differentiation of spermatogonia into spermatocytes. Studies have shown that CIB1 is expressed in spermatogonia, spermatocytes, and spermatids, indicating its role throughout the entire process of spermatogenesis. [8] [15] In mice, CIB1 deficiency has been shown to lead to decreased spermatogonia proliferation and impaired differentiation into spermatocytes, resulting in reduced sperm production and male infertility. [15] In addition, CIB1 has been shown to regulate the expression of genes involved in spermatogenesis, including genes involved in cell proliferation and differentiation. [8] [15]
CIB1 has been shown to interact with RAC3, [16] PSEN2, [17] DNA-PKcs, [18] UBR5 [19] and CD61. [5]
Paxillin is a protein that in humans is encoded by the PXN gene. Paxillin is expressed at focal adhesions of non-striated cells and at costameres of striated muscle cells, and it functions to adhere cells to the extracellular matrix. Mutations in PXN as well as abnormal expression of paxillin protein has been implicated in the progression of various cancers.
Integrin-linked kinase is an enzyme that in humans is encoded by the ILK gene involved with integrin-mediated signal transduction. Mutations in ILK are associated with cardiomyopathies. It is a 59kDa protein originally identified in a yeast-two hybrid screen with integrin β1 as the bait protein. Since its discovery, ILK has been associated with multiple cellular functions including cell migration, proliferation, and adhesion.
Integrin beta-3 (β3) or CD61 is a protein that in humans is encoded by the ITGB3 gene. CD61 is a cluster of differentiation found on thrombocytes.
CD9 is a gene encoding a protein that is a member of the transmembrane 4 superfamily also known as the tetraspanin family. It is a cell surface glycoprotein that consists of four transmembrane regions and has two extracellular loops that contain disulfide bonds which are conserved throughout the tetraspanin family. Also containing distinct palmitoylation sites that allows CD9 to interact with lipids and other proteins.
Proto-oncogene tyrosine-protein kinase Fyn is an enzyme that in humans is encoded by the FYN gene.
PTK2 protein tyrosine kinase 2 (PTK2), also known as focal adhesion kinase (FAK), is a protein that, in humans, is encoded by the PTK2 gene. PTK2 is a focal adhesion-associated protein kinase involved in cellular adhesion and spreading processes. It has been shown that when FAK was blocked, breast cancer cells became less metastatic due to decreased mobility.
Filamin A, alpha (FLNA) is a protein that in humans is encoded by the FLNA gene.
Protein tyrosine kinase 2 beta is an enzyme that in humans is encoded by the PTK2B gene.
Disintegrin and metalloproteinase domain-containing protein 15 is an enzyme that in humans is encoded by the ADAM15 gene.
Ras-related C3 botulinum toxin substrate 3 (Rac3) is a G protein that in humans is encoded by the RAC3 gene. It is an important component of intracellular signalling pathways. Rac3 is a member of the Rac subfamily of the Rho family of small G proteins. Members of this superfamily appear to regulate a diverse array of cellular events, including the control of cell growth, cytoskeletal reorganization, and the activation of protein kinases.
Alpha-actinin-1 is a protein that in humans is encoded by the ACTN1 gene.
Vasodilator-stimulated phosphoprotein is a protein that in humans is encoded by the VASP gene.
Integrin beta-5 is a protein that in humans is encoded by the ITGB5 gene.
Neural precursor cell expressed developmentally down-regulated protein 9 (NEDD-9) is a protein that in humans is encoded by the NEDD9 gene. NEDD-9 is also known as enhancer of filamentation 1 (EF1), CRK-associated substrate-related protein (CAS-L), and Cas scaffolding protein family member 2 (CASS2). An important paralog of this gene is BCAR1.
LIM and senescent cell antigen-like-containing domain protein 1 is a protein that in humans is encoded by the LIMS1 gene.
Integrin beta-1-binding protein 1 is a protein that in humans is encoded by the ITGB1BP1 gene.
Alpha-parvin is a protein that in humans is encoded by the PARVA gene.
Fasciculation and elongation protein zeta-1 is a protein that in humans is encoded by the FEZ1 gene.
Serine/threonine-protein kinase PLK2 is an enzyme that in humans is encoded by the PLK2 gene.
Rap1 GTPase-GDP dissociation stimulator 1 is an enzyme that in humans is encoded by the RAP1GDS1 gene.