TY - JOUR
T1 - A predominantly nuclear protein affecting cytoplasmic localization of β-actin mRNA in fibroblasts and neurons
AU - Gu, Wei
AU - Pan, Feng
AU - Zhang, Honglai
AU - Bassell, Gary J.
AU - Singer, Robert H.
PY - 2002/1/7
Y1 - 2002/1/7
N2 - The localization of β-actin mRNA to the leading lamellae of chicken fibroblasts and neurite growth cones of developing neurons requires a 54-nt localization signal (the zipcode) within the 3′ untranslated region. In this study we have identified and isolated five proteins binding to the zipcode. One of these we previously identified as zipcode binding protein (ZBP)1, a 4-KH domain protein. A second is now investigated in detail: a 92-kD protein, ZBP2, that is especially abundant in extracts from embryonic brain. We show that ZBP2 is a homologue of the human hnRNP protein, KSRP, that appears to mediate premRNA splicing. However, ZBP2 has a 47-amino acid (aa) sequence not present in KSRP. Various portions of ZBP2 fused to GFP indicate that the protein most likely shuttles between the nucleus and the cytoplasm, and that the 47-aa insert promotes the nuclear localization. Expression of a truncated ZBP2 inhibits the localization of β-actin mRNA in both fibroblast and neurons. These data suggest that ZBP2, although predominantly a nuclear protein, has a role in the cytoplasmic localization of β-actin mRNA.
AB - The localization of β-actin mRNA to the leading lamellae of chicken fibroblasts and neurite growth cones of developing neurons requires a 54-nt localization signal (the zipcode) within the 3′ untranslated region. In this study we have identified and isolated five proteins binding to the zipcode. One of these we previously identified as zipcode binding protein (ZBP)1, a 4-KH domain protein. A second is now investigated in detail: a 92-kD protein, ZBP2, that is especially abundant in extracts from embryonic brain. We show that ZBP2 is a homologue of the human hnRNP protein, KSRP, that appears to mediate premRNA splicing. However, ZBP2 has a 47-amino acid (aa) sequence not present in KSRP. Various portions of ZBP2 fused to GFP indicate that the protein most likely shuttles between the nucleus and the cytoplasm, and that the 47-aa insert promotes the nuclear localization. Expression of a truncated ZBP2 inhibits the localization of β-actin mRNA in both fibroblast and neurons. These data suggest that ZBP2, although predominantly a nuclear protein, has a role in the cytoplasmic localization of β-actin mRNA.
KW - KH domain proteins
KW - Nuclear-cytoplasmic trafficking
KW - RNA binding proteins
KW - RNA localization
KW - RNA splicing
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UR - http://www.scopus.com/inward/citedby.url?scp=0037033786&partnerID=8YFLogxK
U2 - 10.1083/jcb.200105133
DO - 10.1083/jcb.200105133
M3 - Article
C2 - 11781334
AN - SCOPUS:0037033786
SN - 0021-9525
VL - 156
SP - 41
EP - 51
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 1
ER -