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Cavin-1 is linked to lipid droplet formation in human hepatic stellate cells

  • Hiroaki YokomoriEmail author
  • Wataru Ando
  • Masaya Oda
Letter to the Editor
  • 16 Downloads

Caveolin-1 (CAV-1), discovered using immunohistocytochemistry as a major component of caveolae localized in plasma membrane caveolae, Golgi apparatus, and trans-Golgi-derived transport vesicles, is expressed either as a soluble cytoplasmic form or as a secreted form, depending on the cell type [1]. Polymerase I and transcript release factor (PTRF)/cavin-1 selectively associate with mature caveolae at the plasma membrane but not Golgi-localized CAV. Interaction of cavin-1 with CAV-1 is not direct, but is possibly mediated through cytoskeletal interactions between microtubules and actin filaments [2].

Lipid droplets (LDs), which originate from the ER surface, are constantly forming, growing, and shrinking [3]. According to the biogenesis of caveolae and LD, the process initiates by synthesis of CAV-1 in the endoplasmic reticulum (ER), followed by its exit to Golgi, where it buds as vesicles and ultimately fuses with the plasma membrane, where it can acquire additional proteins including...

Notes

Supplementary material

795_2019_219_MOESM1_ESM.tif (19.7 mb)
Supplemental Fig. 1 Transmission electron micrographs of CAV-1 (a, b, e, f) showing hepatic stellate cells (HSCs) around the portal tract (a, b) and around the central vein (c, d) in normal liver tissue (a–d) and in cirrhotic liver tissue (e, f): a, c, e low magnification; b, d, f high magnification. a, b: HSCs associated with low-density lipid droplets (LDs). Immunogold particles labeled CAV-1 in small clusters (arrowheads) on the rims of low-density LDs. Arrowheads indicate CAV-1 in the rim. c, d: Immunogold particles labeled CAV-1 in vesicles (black arrowheads) on the rims of low-density, Golgi complex (white arrowheads), and caveolae (white arrowheads). Bars = 2 μm or 200 nm. e, f: Immunogold particle labeling of CAV-1 on ER-like membranes attached to LDs. HSC, hepatic stellate cell. Arrowheads indicate CAV-1-positive particles. Black arrowheads indicate caveolae; white arrows indicate ER-like membranes (TIF 20131 KB)

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Copyright information

© The Japanese Society for Clinical Molecular Morphology 2019

Authors and Affiliations

  1. 1.Department of Internal MedicineKitasato University Medical CenterSaitamaJapan
  2. 2.Department of Clinical Pharmacy, School of PharmacyKitasato UniversityTokyoJapan
  3. 3.Organized Center of Clinical MedicineInternational University of Health and WelfareTokyoJapan

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