Age‐dependent expression of collapsin response mediator proteins (CRMPs) in cat visual cortex

Abstract

The functional properties and anatomical organization of the mammalian visual cortex are immature at birth and develop gradually during the first postnatal weeks. There is a 'critical period' where the cortex is plastic and susceptible to changes in visual input. Knowledge of proteins with a high expression during this period has great importance for the understanding of activity-driven maturation of the brain. The collapsin response mediator protein family consists of five cytosolic phosphoproteins (CRMP1-5) that are involved in neuronal differentiation during the development of the nervous system. They have been implicated in axon guidance and growth cone collapse through their action in the signalling pathway of collapsin/semaphorin. We examined the distribution of the CRMPs throughout the visual cortex of kitten and adult cat by in situ hybridization. While CRMP3 could not be detected in cat forebrain, the other CRMPs showed a higher expression in the immature brain compared to the adult state. Western blotting allowed the quantification of the observed age-dependent differences in the expression of CRMP2, 4 and 5. Moreover, for CRMP2 and 5 we observed a number of development-dependent post-translational modifications. We thus conclude that CRMPs might be important during the normal postnatal development of the visual cortex possibly for the fine-tuning of the specific connections in the brain.

Protein Expression Dynamics during Postnatal Mouse Brain Development

“…Byk et al62 illustrated an identical mRNA expression pattern for CRMP1, 3, and 4 in the rat brain, characterized by an age-dependent decrease. Also, comparable distribution patterns for CRMP1, 2, 4 and 5 in cat brain were described by Cnops and coworkers 59. In general, CRMP levels in the adult brain are reduced and are mainly expressed in areas that retain a certain form of plasticity and/or neurogenesis including the hippocampus and the ventricular zone 63.…”

Stable isotope metabolic labeling suggests differential turnover of the DPYSL protein family

“…Follow up studies will be required to elucidate the exact protein turnover events that lead to the differential isotopologue patterns observed. In mice, rats and cats DPYSL protein family members are reported to be expressed at higher levels at early developmental stages and decreasing levels in adulthood [20][21][22][23]. When we analyzed protein expression by Western Blot using cerebella cytosolic extracts with DPYSL3 (Lifespan BioSciences, Seattle, WA, LS-C 18222) and DPYSL5 (CRMP5, Abcam, Cambridge, UK, ab36203) specific antibodies we found a similar trend irrespective of the 15 N-diet used.…”

Combined age- and trauma-related proteomic changes in rat neocortex: a basis for brain vulnerability

“…Both CRMP2 and moesin associate with microtubules to bring them into proximity with the cell membrane. CRMP2 is regulated in the brain during development and aging (Cnops et al, 2004; Cnops et al, 2006; Fountoulakis et al, 2000; Hamajima et al, 1996; Poon et al, 2004; Poon et al, 2006; Veyrac et al, 2005), as well as in a variety of neuropathologic conditions (Bretin et al, 2006; Carrette et al, 2006; Castegna et al, 2002; Chen et al, 2007; Cid et al, 2007; Cole et al, 2004; Cole et al, 2007; Fujisawa et al, 2008; Iwazaki et al, 2007; Lin and Hsueh, 2008; Putman et al, 1997; Ryan and Pimplikar, 2005; Sultana et al, 2007; Vuaillat et al, 2008; Yoshida et al, 1998; Zhang et al, 2007; Zhao et al, 2006). Yet there is much still to be learned about the appearance and function of this highly regulated mediator of neuroplasticity in the injured and aging brain.…”