A commercial antibody to the human condensin II subunit NCAPH2 cross-reacts with a SWI/SNF complex component

ZNF143 is a transcriptional regulator of nuclear-encoded mitochondrial genes that acts independently of looping and CTCF

Gene expression is orchestrated by transcription factors, which function within the context of a three-dimensional genome. Zinc-finger protein 143 (ZNF143/ZFP143) is a transcription factor that has been implicated in both gene activation and chromatin looping. To study the direct consequences of ZNF143/ZFP143 loss, we generated a ZNF143/ZFP143 depletion system in mouse embryonic stem cells. Our results show that ZNF143/ZFP143 degradation has no effect on chromatin looping. Systematic analysis of ZNF143/ZFP143 occupancy data revealed that a commonly used antibody cross-reacts with CTCF, leading to its incorrect association with chromatin loops. Nevertheless, ZNF143/ZFP143 specifically activates nuclear-encoded mitochondrial genes, and its loss leads to severe mitochondrial dysfunction. Using an in vitro embryo model, we find that ZNF143/ZFP143 is an essential regulator of organismal development. Our results establish ZNF143/ZFP143 as a conserved transcriptional regulator of cell proliferation and differentiation by safeguarding mitochondrial activity.

A commercial ARHGEF17/TEM4 antibody cross-reacts with Nuclear Mitotic Apparatus protein 1 (NuMA)

The Rho family Guanine nucleotide exchange factor (GEF) ARHGEF17 (also known as TEM4) is a large protein with only 3 annotated regions: an N-terminal actin-binding domain, a Rho-specific dbl homology (DH)- pleckstrin homology (PH) type GEF domain and a seven bladed β propeller fold at the C-terminus with unknown function. TEM4 has been implicated in numerous activities that rely on regulation of the cytoskeleton including cell migration, cell-cell junction formation and the spindle assembly checkpoint during mitosis. Here we have assessed the specificity of a TEM4 polyclonal antibody that has been commonly used as a Western blotting and immunocytochemistry probe for TEM4 in mammalian cells. We find that this antibody, in addition to its intended target, cross-reacts with the Nuclear Mitotic Apparatus Protein 1 (NuMA) in Western blotting and immunoprecipitation, and detects NuMA preferentially in immunocytochemistry. This cross-reactivity, with an abundant chromatin- and mitotic spindle-associated factor, is likely to affect the interpretation of experiments that make use of this antibody probe, in particular by immunocytochemistry and immunoprecipitation.