Functional Characteristics of Neutral Amino Acid Transporter in Opossum Kidney (OK) Cells

• 영문명: Functional Characteristics of Neutral Amino Acid Transporter in Opossum Kidney (OK) Cells
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Jae Suk Woo Moon Hwan Park Sae Ok Oh Jin Sup Jung Yong Keun Kim Sang Ho Lee
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제1권 제2호, 185~193쪽, 전체 9쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1997.01.01

영문 초록

The characteristics of Na⁺-dependent cycloleucine uptake was investigated in OK cells with regard to substrate specificity and regulation by protein kinase C (PKC). Inhibition studies with different synthetic and natural amino acids showed a broad spectrum affinity to neutral amino acids regardless of their different side chains including branched or aromatic, indicating that the Na⁺-dependent cycloleucine uptake in OK cells is mediated by System B^o or System B^o-like transporter rather than the classical System A or ASC. Phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate, but not 4α-PMA elicited a time-dependent biphasic stimulation of Na⁺-dependent cycloleucine uptake, which produced early transient peak at 30 min and late sustained peak at 180min. Both the early and late stimulations by PMA were due to an increase in Vmax and not due to a change in Km. PKC inhibitors blocked both the early and late stimulation by PMA, while protein synthesis inhibitors blocked the late stimulation only. These results suggest the existence and regulation by PKC of System B^o or System B^o-like broad spectrum transport system for neutral amino acids in OK cells.

키워드

Neutral amino acid transport Opossum kidney cells System B^o Phorbol ester Protein kinase C