Insulin‐like growth factor‐II (IGF‐II) mRNA‐binding protein‐2 (IMP2) is one of the three homologs (IMP1–3) that play important roles in the posttranscriptional regulation of gene expression in several tissues. IMP1/ZBP1 (zipcode binding protein) has been shown to play important roles in axon guidance and regeneration by regulating the localization and translation of specific mRNAs. However, the function of IMP2 is least understood, largely because an isoform‐specific antibody is not available, which makes the conventional techniques to locate protein expression not feasible. We custom made an IMP2‐specific antibody. We used Western blot and immunocytochemistry to test its specificity on cultured cells following over expression of IMP 1–3 isoforms, respectively. Using this IMP2‐specific antibody, we examined IMP2 expression in the mouse nervous system. We found that IMP2 expression in the nervous system is sustained postnatally, unlike that of IMP1 and IMP3. Ongoing experiments are aimed at further understanding IMP2 expression patterns during injury and assessment of its role to facilitate mRNA localization during axon regeneration in the adult nervous system.This work is supported by the Department of Anatomy, PCOM and Center for Chronic Disorders of Aging (CCDA).

The three homologs of insulin like growth factor‐II (IGF‐II) mRNA binding protein (IMP) play an essential role in the posttranscriptional regulation of gene expression in nervous tissue. IMP1/ZBP1 (zipcode binding protein) regulates the localization and translation of specific mRNAs allowing for axon guidance and regeneration. Additionally, previous studies show that IMP1 and IMP3 expression decreases dramatically after birth, whereas IMP2 is sustained in in brain, liver and other organs throughout life (Leeds et al., 1997; Mueller‐Pillasch et al., 1999; Nielsen et al., 1999; Hansen et al., 2004; Gu et al., 2004; Hammer et al., 2005). Of the three homologs, IMP2 is least understood. Our pilot data implicates that IMP2 may play a role in axon regeneration by localizing specific mRNAs. Understanding IMP2 expression pattern is fundamental to further investigation of its functions. We hypothesized that IMP2 is present in both the central and peripheral nervous systems throughout life. Using a custom made IMP2‐specific antibody, along with immunohistochemistry, Western Blot, and primary dorsal root ganglion (DRG) culture we examined the expression of IMP2 in the spinal cord and DRG of the mouse at embryonic, postnatal, and adult stages of life. We found that IMP2 expression is present in both the spinal cord and DRG through all developmental stages of life. Ongoing experiments are focused on the role of IMP2 in axon regeneration in the adult nervous system.