Coronin 3 and its role in murine brain morphogenesis

Abstract

Coronins belong to the fundamental WD40-repeat proteins. They are mainly found at the submembraneous area, they bind F-actin in vitro, and most of the seven mammalian coronins have unclear roles. Coronin 3 is abundantly expressed in the adult CNS. All murine brain areas express coronin 3 during embryogenesis and the first postnatal stages. Expression in grey matter decreases postnatally, except for hippocampal pyramidal and dentate gyrus neurons, and cerebellar Purkinje cells, while levels in white matter increase in the course of myelination. Consistently, coronin 3 is abundant in differentiating neuro-2a and PC-12 cells and in primary oligodendrocytes. Treatment with PKC activator PMA reduced coronin 3 protein levels. To address its functions, neuro-2a and PC-12 cells were transfected with GFP-tagged coronin 3 versions. Full-length coronin 3 among other areas localized to outgrowing neurites, whereas truncated proteins efficiently suppressed neurite formation. Our results favour a role for coronin 3 in neuron morphogenesis and possibly migration.

Coronin proteins as multifunctional regulators of the cytoskeleton and membrane trafficking

“…Coronins 3 and 7 demonstrate highly dynamic expression patterns in the embryonic brain implying that differential activity of those proteins may participate in the regulation of brain development, probably together with other coronins expressed in the developing brain. (39,49) Although some coronins have been studied in detail, biochemical and functional properties of their majority is unclear. Future experiments need to be directed at functional properties of coronin proteins.…”

CAP2, cyclase-associated protein 2, is a dual compartment protein

“…Cell lines were cultured as described previously [15], and transfections were done as described [16,17]. PAM212 cells [18] were cultured in tissue culture dishes (Falcon) in DMEM (Gibco) supplemented with Chelex-100 (Bio-Rad) treated 10 % heat-inactivated fetal calf serum, 1 mM pyruvate, 2 mM glutamine, 50 mg/ml streptomycin, 50 units/ml penicillin and 0.05 mM CaCl 2 (low calcium medium).…”

Crn7 Interacts with AP-1 and Is Required for the Maintenance of Golgi Morphology and Protein Export from the Golgi

“…Fine chemicals were purchased from Sigma unless indicated otherwise. Short interfering 21-mer RNA oli-gonucleotides (siRNA) 3 targeted against human Crn7 (designed and supplied by Qiagen): siRNA(1) 123 , siRNA(2) ϩ520 , siRNA(3) 1452 , siRNA (4) 163 , siRNA(5) 2639 , siRNA (6) 2055 , siRNA(7) ϩ60 , siRNA (8) 2454 . Lower indices indicate the starting positions of corresponding sequences in the Crn7 mRNA; oligonucleotides 2 and 7 targeted fragments of the 3Ј-region of Crn7 mRNA starting 520 and 60 bases after the last coding base, respectively.…”