SEMA4C

SEMA4C (Semaphorin 4C) is a protein encoded by the SEMA4C gene in humans. It belongs to the Class 4 semaphorin family, a group of transmembrane and secreted signaling molecules known to play diverse roles in axon guidance, immune regulation, and angiogenesis.

Function:

SEMA4C is involved in cell-cell communication, acting as a ligand that binds to receptor proteins on other cells. Its primary role appears to be in regulating cell migration and adhesion. It has been implicated in various biological processes, including:

• Nervous System Development: SEMA4C contributes to the proper formation and wiring of neural circuits. It influences axon guidance, helping neurons find their correct targets during development.
• Immune System Regulation: SEMA4C plays a role in immune cell activation and differentiation. It can modulate the function of T cells and other immune cells, influencing inflammatory responses.
• Angiogenesis: SEMA4C influences the formation of new blood vessels. This is relevant in both normal development and in pathological conditions such as tumor growth.
• Cancer Development: Aberrant expression or signaling of SEMA4C has been observed in various cancers. It can promote tumor growth, metastasis, and angiogenesis in certain contexts, while in others it may exhibit tumor-suppressive properties.

Structure:

Semaphorins are characterized by a conserved ~500 amino acid sema domain at the N-terminus. SEMA4C is a type I transmembrane protein, meaning it has a single transmembrane domain that anchors it to the cell membrane. The extracellular portion of SEMA4C contains the sema domain, as well as other domains such as an immunoglobulin-like domain and a PSI (plexins, semaphorins, integrins) domain. The intracellular portion contains sequences involved in signal transduction.

Interactions:

SEMA4C interacts with other proteins, including its receptors. Although the precise receptors for SEMA4C remain an area of ongoing research, some studies suggest that Plexin receptors can mediate SEMA4C signaling. Further investigation is necessary to fully elucidate the receptor binding partners and downstream signaling pathways activated by SEMA4C in different cellular contexts.

Clinical Significance:

Because of its roles in development, immunity, and angiogenesis, SEMA4C has been implicated in various diseases.

• Neurological Disorders: Alterations in SEMA4C expression or function may contribute to neurological disorders.
• Autoimmune Diseases: SEMA4C's role in immune regulation suggests it may be involved in the pathogenesis of autoimmune diseases.
• Cancer: SEMA4C's complex role in tumor biology suggests it may be a potential therapeutic target in cancer. However, further research is needed to understand its precise role in different cancer types.

Further Research:

The precise mechanisms of action of SEMA4C, its full range of receptor interactions, and its roles in various diseases remain areas of active investigation.