【干冰】K29-Linked Di-Ubiquitin

Ubiquitin Chain Synthesis

Several important signaling processes depend on the tagging of cellular proteins with “polyubiquitin chains”—ubiquitin polymers whose building blocks are connected by isopeptide bonds between G76 of one ubiquitin and a specific lysine residue

Studies of the Ubiquitin Proteasome System

can, in general, be covalently modified by polypeptides, resulting in alterations in their fate and function. The first?identified and most well studied of these modifying polypeptides is ubiquitin. Although targeting for proteasomal degradation is the best

隐睾病 cryptorchi（di）sm

　　隐睾病 cryptorchi（ di） sm 在哺乳类，其应下降到阴囊的睾丸停留在腹腔内，这种睾丸称为隐睾或留睾（ setentio testis）。隐睾是构成不妊的原因之一，还常发生肿瘤。在实验上，可将动物睾丸由阴囊推回腹腔然后将其缝在腹膜上或把腹股沟管缝合造成实验隐睾。由于腹腔内的温度比阴囊内温度高数度，所以精子的生成受到障碍。但间隙细胞可继续分泌雄性激素。在正常状态下，也有发生精巢下降的动物，如犰狳、鲸、熊、象等。