Comparison of Three Members of the Cysteine-rich Protein Family Reveals Functional Conservation and Divergent Patterns of Gene Expression

Abstract

Members of the cysteine-rich protein (CRP) family are evolutionarily conserved proteins that have been implicated in the processes of cell proliferation and differentiation. In particular, one CRP family member has been shown to be an essential regulator of cardiac and skeletal muscle development. Each of the three vertebrate CRP isoforms characterized to date is composed of two copies of the zinc-binding LIM domain with associated glycine-rich repeats. In this study, we have addressed the biological significance of the CRP multigene family by comparing the subcellular distributions, biochemical properties, and expression patterns of CRP1, CRP2, and CRP3/MLP. Our data reveal that all three CRP family members, when expressed in adherent fibroblasts, associate specifically with the actin cytoskeleton. Moreover, all three CRP isoforms are capable of interacting with the cytoskeletal proteins ␣-actinin and zyxin. Together, these observations suggest that CRP family members may exhibit overlapping cellular functions. Differences between the three CRPs are evident in their protein expression patterns in chick embryos. CRP1 expression is detected in a variety of organs enriched in smooth muscle. CRP2 is restricted to arteries and fibroblasts. CRP3/MLP is dominant in organs enriched in striated muscle. CRP isoform expression is also developmentally regulated in the chick. Our findings suggest that the three CRP family members perform similar functions in different muscle derivatives. The demonstration that all members of the CRP family are associated with cytoskeletal components that have been implicated in the assembly and organization of filamentous actin suggests that CRPs contribute to muscle cell differentiation via effects on cytoarchitecture.Members of the cysteine-rich protein (CRP) 1 family are evolutionarily conserved proteins that have been implicated in myogenesis. CRPs exhibit a common domain structure, being composed primarily of two tandemly arrayed LIM domains (1, 2). Each LIM domain, defined by the consensus sequence

Vascular Response to Hypoxic Preconditioning in the Immature Brain

“…In addition, Pdgra (Heldin and Westermark, 1999), Prx1 (Bergwerff et al, 1998), Crsp2 (Louis et al, 1997), and Anxa2 (Rescher and Gerke, 2004) were upregulated. Changes in the expression of vasoregulatory genes induced after PC include adrenomedullin (Lang et al, 1997), apelin (Lee et al, 2000), Agtrap (Daviet et al, 1999), Adora A2a and Adora A2b (Coney and Marshall, 1998), Ednra (Arai et al, 1990), and NOS3 (Griffith and Stuehr, 1995), which also could be important to explain the altered CBF response during HI.…”

Genome‐wide examination of myoblast cell cycle withdrawal during differentiation

“…tant role in myogenesis and in the promotion of myogenic differentiation (Arber et al, 1994(Arber et al, , 1997Louis et al, 1997). The activity of MLP during the myogenic program, however, comes late in differentiation.…”

“…MEF2 transcriptional activity, which follows MyoD and myogenin (Edmondson et al, 1994;Subramanian and Nadal-Ginard, 1996), is required for expression of an MLP homolog in Drosophila melanogaster (Stronach et al, 1999). Consistent with the timing of its expression, MLP is thought to control actin assembly by interacting with two cytoskeleton protein, ␣-actinin and zyxin (Louis et al, 1997;Stronach et al, 1999). Although previous results demonstrated that MLP was induced at the onset of C2C12 differentiation (Arber et al, 1994), our results that showed early suppression with subsequent induction of MLP (Table 4), are consistent with the observed timing of its function.…”

Expression of the Gene Encoding the LIM Protein CRP2: A Developmental Profile

“…Studies in both chick and rat have revealed that CRP2 (also referred to as SmLIM) is present at highest levels in arterial samples (Jain et al 1996;Louis et al 1997), and subsequent work has focused on a potential role for CRP2 in the vascular system (Jain et al 1998). Here we describe the pattern of csrp2 expression in the developing and adult mouse.…”

“…We have described the gene encoding CRP1 (in vertebrates the gene family that encodes the CRPs is referred to as csrp ) (Weiskirchen et al 1995) as a smooth muscle marker in the mouse (Henderson et al 1999). CRP3, also referred to as the muscle LIM protein (MLP), is found exclusively in striated muscle (Arber et al 1997;Louis et al 1997). Ablation of the csrp3/mlp gene in mouse is associated with a dilated cardiomyopathy that may result from irregularities in intercalated discs, sites of cell adhesion, and mechanical coupling in cardiac muscle (Arber et al 1997;Ehler et al 2001).…”