The Inner Nuclear Membrane Has a Unique Lipid Signature

Although the inner nuclear membrane (INM) is generally considered to be continuous with the outer nuclear membrane (ONM) and connected to the remaining endoplasmic reticulum (ER), it has been well recognized that it is functionally distinct, having a unique protein composition. It has increasingly been recognized, however, that the INM also differs from the ONM and the other ER domains in its lipid composition. It is an intriguing proposition that the unique lipid profile of the INM is intricately linked to its specialized functions related to the nuclear events. Despite rapid progress in recent years in our understanding of the unique lipid profile of the INM and its role in the control of nuclear functions, there is a lot that remains to be understood. This review summarizes recent advances in characterizing the INM lipid composition and lipid synthetic pathways including their possible roles in the control of nuclear functions. Additionally, it discusses current challenges and areas deserving further investigation.