BACKGROUND: @entity1078 [ @entity17418 ] is a critically important regulatory phospholipid found in the plasma membrane of all eukaryotic cells. In addition to being a precursor of important second messengers, @entity17418 also regulates ion channels and transporters and serves the endocytic machinery by recruiting clathrin adaptor proteins. Visualization of the localization and dynamic changes in @entity17418 levels in living cells is critical to understanding the biology of @entity17418 . This has been mostly achieved with the use of the pleckstrin homology (PH) domain of PLCdelta1 fused to GFP. Here we report on a comparative analysis of several recently-described @entity375 PH domains as well as the @entity1 Tubby domain to evaluate their usefulness as @entity17418 imaging tools. RESULTS: All of the @entity375 PH domains that have been previously shown to bind @entity17418 showed plasma membrane localization but only a subset responded to manipulations of plasma membrane @entity17418 . None of these domains showed any advantage over the PLCdelta1PH-GFP reporter and were compromised either in their expression levels, nuclear localization or by causing peculiar membrane structures. In contrast, the Tubby domain showed high membrane localization consistent with @entity17418 binding and displayed no affinity for the soluble headgroup, @entity19818 . Detailed comparison of the Tubby and PLCdelta1PH domains showed that the Tubby domain has a higher affinity for membrane @entity17418 and therefore displays a lower sensitivity to report on changes of this lipid during phospholipase C activation. CONCLUSION: These results showed that both the PLCdelta1PH-GFP and the GFP-Tubby domain are useful reporters of @entity17418 changes in the plasma membrane, with distinct advantages and disadvantages. While the PLCdelta1PH-GFP is a more sensitive reporter, its Ins(1,4,5)P3 binding may compromise its accuracy to measure @entity17418 changes. The Tubby domain is more accurate to report on @entity17418 but its higher affinity and lower sensitivity may limit its utility when phospholipase C activation is only moderate. These studies also demonstrated that similar changes in @entity17418 levels in the plasma membrane can differentially regulate multiple effectors if they display different affinities to @entity17418 .

Live cell imaging with protein domains capable of recognizing XXXX ; a comparative study.

@entity1 :: ('9606', 'Species') :: ['mammalian'] @entity17418 :: ('MESH:D019269', 'Chemical') :: ['PtdIns(4,5)P2'] @entity1078 :: ('CHEBI:18348', 'Chemical') :: ['Phosphatidylinositol 4,5-bisphosphate'] @entity375 :: ('4932', 'Species') :: ['yeast'] @entity19818 :: ('CHEBI:340804', 'Chemical') :: ['Ins(1,4,5)P3']
@entity1078 :: (CHEBI:18348,Chemical) :: ['phosphatidylinositol 4,5-bisphosphate']
