{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\nSMIM32, also known as Ermin or juxtanodin, is a cytoskeletal regulator prominently expressed in differentiated oligodendrocytes. In the central nervous system, it localizes to the outer cytoplasmic lip of the myelin sheath and paranodal loops, where its actin‐binding properties facilitate the formation of F-actin–rich protrusions essential for the late wrapping and compaction phases of myelinogenesis. Interestingly, while SMIM32 lies within a chromosomal region (5q31.2) frequently deleted in myelodysplastic syndromes, systematic resequencing studies did not reveal somatic point mutations or submicroscopic deletions in SMIM32, suggesting that in this context, the pathology is mediated by haploinsufficiency of multiple genes rather than a singular genetic lesion."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "1"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nIn addition to its role in myelinating oligodendrocytes, SMIM32 is expressed in the retinal pigment epithelium (RPE), where it co-localizes with F-actin at key subcellular locations such as the apices and basal regions of RPE cells. Experimental overexpression in cultured RPE cells promotes the formation of actin stress fibers, redistributes F-actin toward the cell periphery, and enhances cell spreading. These findings suggest that SMIM32 may be crucial for functions related to molecular transport, phagocytosis, and the maintenance of the outer blood-retinal barrier, with potential implications in retinal disorders."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n"}]}, {"type": "t", "text": "\n\n"}, {"type": "p", "children": [{"type": "t", "text": "\nTogether, the data indicate that SMIM32 is a multifunctional cytoskeletal component that modulates actin dynamics to support both the complex structural remodeling required for efficient myelin sheath formation and the specialized architecture of RPE cells. Although small-scale mutations in SMIM32 are not a common driving force in myelodysplastic syndromes, its role within the 5q31.2 interval underscores the broader significance of coordinated gene dosage in maintaining normal cellular function across diverse tissues."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "3"}]}, {"type": "t", "text": "\n"}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Damian Brockschnieder, Helena Sabanay, Dieter Riethmacher, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Ermin, a myelinating oligodendrocyte-specific protein that regulates cell morphology."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Neurosci (2006)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1523/JNEUROSCI.4317-05.2006"}], "href": "https://doi.org/10.1523/JNEUROSCI.4317-05.2006"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "16421295"}], "href": "https://pubmed.ncbi.nlm.nih.gov/16421295"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Timothy A Graubert, Michelle A Payton, Jin Shao, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Integrated genomic analysis implicates haploinsufficiency of multiple chromosome 5q31.2 genes in de novo myelodysplastic syndromes pathogenesis."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0004583"}], "href": "https://doi.org/10.1371/journal.pone.0004583"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19240791"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19240791"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Fengyi Liang, Ji Hyun Hwang, Nicholas Weiwei Tang, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Juxtanodin in retinal pigment epithelial cells: Expression and biological activities in regulating cell morphology and actin cytoskeleton organization."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "J Comp Neurol (2018)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1002/cne.24301"}], "href": "https://doi.org/10.1002/cne.24301"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "28815590"}], "href": "https://pubmed.ncbi.nlm.nih.gov/28815590"}]}]}]}