We have recently identified ZNF185 as a gene that is downregulated in prostate cancer (PCa), in part via epigenetic alteration, and maybe associated with disease progression. In this study, we cloned the ZNF185 cDNA from normal human prostate tissues and investigated its biological function. We show that ZNF185 is a novel actin-cytoskeleton-associated Lin-l 1, Isl-1 and Mec-3 (LIM) domain-containing protein that localizes to F-actin structures, and is enriched at focal adhesions. We find that the NH 2 -terminal region, which we designate the actintargeting domain, facilitates ZNF185 binding to actin in vitro and is both necessary and sufficient to mediate actin-cytoskeleton targeting of ZNF185, whereas the LIM domain, which is localized in the COOH-terminus is dispensable for this phenomenon. Interestingly, ectopic expression of full-length ZNF185, but not a mutant lacking the actin-targeting domain, could suppress proliferation and anchorage-independent growth of PCa cells. Together, our data suggest that ZNF185 may function as a tumor-suppressor protein by associating with the actincytoskeleton.

The mammalian lung is a highly complex organ due to its branched, tree-like structure and diverse cellular composition. Recent efforts using state-of-the-art genetic lineage tracing and single-cell transcriptomics have helped reduce this complexity and delineate the ancestry and fate of various cell subpopulations during organogenesis, homeostasis and repair after injury. However, mesenchymal cell heterogeneity and function in development and disease remain a longstanding issue in the lung field. In this study, we break down smooth muscle heterogeneity into the constituent subpopulations by combining in vivo lineage tracing, single-cell RNA sequencing and in vitro organoid cultures. We identify a repair-supportive mesenchymal cell (RSMC) population that is distinct from pre-existing airway smooth muscle cells (ASMC) and is critical for regenerating the conducting airway epithelium. Progenitors of RSMCs are intertwined with airway smooth muscle, undergo active WNT signaling, transiently acquire the expression of the smooth muscle marker ACTA2 in response to epithelial injury and are marked by PDGFRα expression. Our data simplify the cellular complexity of the peribronchiolar domain of the adult lung and represent a forward step towards unraveling the role of mesenchymal cell subpopulations in instructing epithelial behavior during repair processes.

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