Nuclear localization signal in human hnRNP L

다국어 초록 (Multilingual Abstract)

The heterogeneous nuclear ribonucleoprotein (hnRNP) L is an abundant nuclear protein and is one of the major pre-mRNA binding proteins in human cells. The amino acid sequence of hnRNP L contains four loosely conserved RNP-concensus RNA-binding domains. In previous report, it was shown that the amino terminal 140 amino acids of the hnRNP L were necessary and sufficient for nuclear localization. In order to define the minimal region of NLS in hnRNP L, a series of amino terminal and carboxy terminal deletions of hnRNP L were fused to the 3' end of the myc epitope-tagged chicken muscle pyruvate kinase (PK) cDNA. The subcellular distribution of transiently expressed polypeptides was examined by immunofluorescence microscopy. Here we report that the nuclear localization signal (NLS) sequence of hnRNP L protein consists of 24-GRAPKRLKT-32 sequences and seems to be a member of classical NLS, the single basic domain. The construct with amino terminal 23 amino acids deletion is still able to confer complete nuclear localization onto PK, a cytoplasmic reporter protein. However, the shorter construct in which amino terminal 35 amino acids were deleted completely lost the capability of targeting of cytoplasmic PK to the nucleus.

목차 (Table of Contents)

• INTRODUCTION
• MATERIALS AND METHODS
• Plasmid constructions
• Cell culture and transfection
• Immunofluorescence microscopy
• RESULTS AND DISCUSSION
• Determination of NLS sequence of hnRNP L
• Confirmation of 24-GRAPKRLKT-32 residues as an NLS of hnRNP L by studygin with myc-PK-amino terminal deletions of hnRNP L
• REFERENCES