40LoVe and Samba are involved in Xenopus neural development and functionally distinct from hnRNP AB.
Heterogeneous nuclear ribonucleoproteins (hnRNPs) comprise a large group of modular RNA-binding proteins classified according to their conserved domains. This modular nature, coupled with a large choice of alternative splice variants generates functional diversity. Here, we investigate the biological differences between 40LoVe, its splice variant Samba and its pseudoallele hnRNP AB in neural development. Loss of function experiments lead to defects in neural development with reduction of eye size, which stem primarily from increased apoptosis and reduced proliferation in neural tissues. Despite very high homology between 40LoVe/Samba and hnRNP AB, these proteins display major differences in localization, which appear to be in part responsible for functional differences. Specifically, we show that the 40Love/Samba carboxy-terminal domain (GRD) enables nucleocytoplasmic shuttling behavior. This domain is slightly different in hnRNP AB, leading to nuclear-restricted localization. Finally, we show that shuttling is required for 40LoVe/Samba function in neural development.
Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
Maria
M
Andreou
Department of Cell and Developmental Biology, Universidade de São Paulo, São Paulo, Brazil.
Chao Yun Irene
CY
Yan
Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
Paris A
PA
Skourides
D000595:Amino Acid Sequence; D000818:Animals; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D008969:Molecular Sequence Data; D009420:Nervous System / Q000254:growth & development* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014981:Xenopus; D029867:Xenopus Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*
C544068:HNRNPAB protein, Xenopus; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D029867:Xenopus Proteins; C539177:samba protein, Xenopus