• Journal of Life Science
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• v.27 no.6
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• pp.673-679
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• 2017

Microtubules are long rods in the cytoplasm of cells that plays a role in cell motility and intracellular transport. Microtubule-based transport by motor proteins is essential in intracellular transport. Kinesin 1 is a molecular motor protein that mediates the intracellular transport of various membranous vesicles, mRNAs, and proteins along microtubules. It is comprised of two heavy chains (KHCs, also called KIF5s) and two light chains (KLCs). KIF5s bear a motor domain in their amino (N)-terminal regions and interact with various cargoes through the cargo-binding domain in their carboxyl (C)-terminal regions. To identify proteins interacting with KIF5B, yeast two-hybrid screening was performed, and a specific interaction with the cytoplasmic linker protein 170 (CLIP-170), a plus end microtubule-binding protein, was found. The coiled-coil domain of CLIP-170 is essential for interactions with KIF5B in the yeast two-hybrid assay. CLIP-170 bound to the cargo-binding domain of KIF5B. Also, other KIF5s, KIF5A and KIF5C, interacted with CLIP-170 in the yeast two-hybrid assay. In addition, glutathione S-transferase (GST) pull-downs showed that KIF5s specifically interacted with CLIP-170. An antibody to KIF5B specifically co-immunoprecipitated CLIP-170 associated with KIF5B from mouse brain extracts. These results suggest that kinesin 1 motor protein may transport CLIP-170 in cells.

• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.119-136
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• 1998

The lipids of milk provide energy and many essential nutrients for the newborn animal. They also have distinctive physical properties that affect the processing of dairy products. Milk fat globules mainly consist of neutral lipids like triacylglycerols, whereas the globule membranes contain the complex lipids mostly, Phospholipids are a small but important fraction of the milk lipids and are found mainly in the milk fat globule membrane and other membranous material in the skim-milk phase. The milk fats of ruminant animals are characterized by the presence of relatively high concentrations of short-chain fatty acids, especially butyric and hexanoic acids, which are rarely found in milks of non-ruminants. The fatty acids of milk lipids arise from de novo synthesis in the mammary gland and uptake from the circulating blood. The fatty acid compositions of milks are usually complex and distinctive, depending on the nature of the fatty acids synthesized de novo in the mammary gland and those received from the diet in each species. The content and composition of milks from different species vary widely; presumably, these are evolutionary adaptations to differing environments. The actual process by which these globules are formed is unkonwn, but there are indications that triglyceride-containing vesicles which bleb from endoplasmic reticulum may serve as nucleation sites for globules. Recent studies on milk have centred on the manipulation of milk lipids to increase specific fatty acids, i.e. 20-carbon omega-3 fatty acids (eicosapentaenoic acid 20:5n3, decosahexaenoic acid 22:6n3) from marine sources because the fatty acids are closely associated with a decreased risk of coronary heart disease.

• Journal of Life Science
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• v.7 no.4
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• pp.392-401
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• 1997

The poliovirus is a small, and non-enveloped virus. The RNA genome of poliovirus is continuous, linear, and has a single open reading frame. This polyprotein precursor is cleaved proteolytically to yield mature products. Most of the cleavages occur by viral protease. The mature proteins derived from the P1 polyprotein precursor are the structural components of the viral capsid. The initial cleavage by 2A protease is indirectly involved in the cleavage of a cellular protein p220, a subunit of the eukaryotic translation initiation factor 4F. This cleavage leads to the shut-off of cap-dependent host cell translation, and allows poliovirus to utilize the host cell machinery exclusively for translation its own RNA, which is initiated by internal ribosome entry via a cap-independent mechanism. The functional role of the 2B, 2C and 2BC proteins are not much known. 2B, 2C, 2BC and 3CD proteins are involved in the replication complex of virus induced vesicles. All newly synthesized viral RNAs are linked with VPg. VPg is a 22 amino acid polypeptide which is derived from 3AB. The 3C and 3CD are protease and process most of the cleavage sites of the polyprotein precursor. The 3C protein is also involved in inhibition of RNA polymerase II and III mediated transcription by converting host transcription factor to an inactive form. The 3D is the RNA dependent RNA polymerase. It is known that poliovirus replication follows the general pattern of positive strand RNA virus. Plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA is transcribed into complementary minus strand RNA that, in turn, is transcribed for the synthesis of plus strand RNA strands. Poliovirus RNA synthesis occurs in a membranous environment but how the template RNA and proteins required for RNA replication assemble in the membrane is not much known. The RNA requirements for the encapsidation of the poliovirus genome (packaging signal) are totally unknown. The poliovirus infection cycle lasts approximately 6 hours.