MYCL1

MYCL1, also called L-Myc, is a gene that encodes a member of the MYC family of transcription factors. The L-Myc protein is a basic helix-loop-helix leucine zipper (bHLHZ) transcription factor that forms heterodimers with MAX and binds to E-box DNA sequences to regulate transcription of genes involved in cell growth, metabolism, and differentiation. It shares structural features with other MYC family members and can promote cell proliferation when aberrantly expressed.

Expression of MYCL1 is developmentally regulated and occurs in multiple human tissues. In normal biology, L-Myc participates in developmental programs and helps balance cellular proliferation and differentiation.

In cancer, MYCL1 can act as an oncogene when amplified or overexpressed. Amplifications and/or overexpression have been reported in a subset of cancers, notably some cases of small cell lung cancer and other neuroendocrine tumors, where L-Myc may contribute to tumor growth and survival. The gene is one of several MYC family members that may be dysregulated in cancer, and its status can influence tumor biology and responses to therapies under investigation.

As with other MYC proteins, L-Myc activity is regulated by upstream signaling, interactions with MAX, and post-translational modifications that control stability and transcriptional activity. The MYCL1 gene and its protein are subjects of ongoing research for their roles in development and oncogenesis, as well as their potential as therapeutic targets in cancers exhibiting MYCL1 dysregulation.