ALDH1L1, or Aldehyde Dehydrogenase 1 Family Member L1, is a significant protein within the human body. This protein is involved in various cellular processes fundamental to maintaining overall health. Its activity has broad implications across biological systems. Understanding its functions provides insights into how the body manages complex biochemical reactions.
Understanding ALDH1L1
ALDH1L1 is an enzyme, a protein that accelerates biochemical reactions. It is encoded by the ALDH1L1 gene and belongs to the aldehyde dehydrogenase family. This protein is primarily located in the cytoplasm of cells, the jelly-like substance that fills cells and surrounds organelles. While found throughout the body, ALDH1L1 is particularly abundant in tissues like the liver and kidneys, and is also expressed in the brain.
ALDH1L1’s Role in Cellular Metabolism
A central function of ALDH1L1 is its participation in folate metabolism, often referred to as one-carbon metabolism. Folate, or vitamin B9, is a coenzyme that carries one-carbon units, small chemical groups involved in many biochemical reactions. ALDH1L1 specifically acts as a 10-formyltetrahydrofolate dehydrogenase.
In this enzymatic reaction, ALDH1L1 converts 10-formyltetrahydrofolate, NADP+, and water into tetrahydrofolate, NADPH, and carbon dioxide. This conversion effectively removes one-carbon groups from the folate pool by oxidizing them into CO2, regulating their availability for various biosynthetic processes. This process supports the synthesis of purines and thymidylate (DNA building blocks), and influences amino acid metabolism, such as serine and glycine.
ALDH1L1 and Neurological Function
ALDH1L1 is highly expressed in the nervous system, particularly in astrocytes, which are star-shaped glial cells that support neurons in the brain and spinal cord. Astrocytes are involved in maintaining brain health by providing metabolic support to neurons, regulating blood flow, and participating in immune responses within the brain. ALDH1L1 is considered a specific marker for astrocytes and is found in both their cell bodies and extensive processes.
Its presence in astrocytes suggests involvement in supporting neuronal metabolism and brain function. It may contribute to regulating neurotransmitter synthesis and protecting against oxidative stress. Research indicates ALDH1L1 is expressed in neurogenic regions and postnatal neural stem cells, hinting at a role in neural development. While its precise functions in neural development are still being explored, its high expression in astrocytes highlights its importance for brain health.
ALDH1L1 in Broader Health Contexts
Beyond its roles in cellular metabolism and neurological function, ALDH1L1 has emerging connections to broader health conditions. Its involvement in folate and one-carbon metabolism links it to processes that impact cell growth and proliferation. This has led to investigations into its role in cancer.
ALDH1L1 is often downregulated or silenced in human cancers, and its loss can correlate with tumor aggressiveness. Re-expression of ALDH1L1 in cancer cells can inhibit proliferation and induce apoptosis, suggesting a potential role as a tumor suppressor. Dysregulation of ALDH1L1 has also been implicated in metabolic disorders due to its influence on amino acid metabolism (e.g., glycine and serine levels) and its contribution to NADPH generation. ALDH1L1’s role in formate oxidation also suggests a connection to methanol detoxification pathways.